Дисертації з теми "Microwave microscopy"
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1
Barker, Duncan James. "Evaluation of microwave microscopy for dielectric characterisation." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1422/.
Повний текст джерелаАнотація:
A widely used analytical, image charge, model of the SNMM was analysed for the first time in terms of its ability to predict the response of the SNMM to both bulk and thin film dielectrics. For the first time it was shown that the uncertainty in fitting to the model reduces from 10% to 5% when the length of the tip protruding from within the cavity is reduced from 2mm to 1mm. A 5% uncertainty in fitting to the image charge model for the measurement of the relative permittivity of bulk samples is demonstrated.
2
Kleismit, Richard A. "EVANESCENT MICROWAVE MICROSCOPY OF PORCINE SKIN TISSUE." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1221859953.
Повний текст джерела
3
Cordoba, Erazo Maria Fernanda. "Near-field Microwave Microscopy for Surface and Subsurface Characterization of Materials." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5930.
Повний текст джерелаАнотація:
This dissertation presents an investigation on the capabilities of Near-Field Microwave Microscopy (NFMM) for the characterization of surface and subsurface materials. Subsurface characterization refers to the detection, differentiation and imaging of dielectric, and metallic features that are coated with an insulating layer. The design, simulation and modeling, and testing of a dielectric resonator (DR)-based NFMM and a coaxial transmission line resonator-based NFMM are discussed in detail in this work. Additionally, materials differentiation and imaging capabilities of each microscope are examined using several bulk samples, liquids, GaAs MMIC circuits, and gold/glass testing patterns.
The 5.7 GHz DR-based NFMM uses a microwave probe that consists of a commercial gold-coated probe tip coupled to a DR through a non-resonant microstrip line. The probe is enclosed in an aluminum cavity to preserve the quality factor of the probe (Q=986) and therefore to enhance its sensitivity. The development of a lumped-element model of this DR-based probe is discussed in this work. Characteristics of this design are its high Q and the ability to resolve differences in permittivity (E’r) of insulting bulk samples and liquids as small as ∆E’r =1.75 and ∆E’r =0.04, respectively. The imaging capabilities of this design were verified using a GaAs MMIC phase shifter. It was found that a 10 um wide microstrip line is successfully resolved and that the spatial resolution of the microscope is 50 um when using a tungsten tip with an apex radius of 25 um. Additionally, measurement of the electrical resistance of an additive manufactured resistor was measured using the DR-based NFMM without the need of contacts. The percent difference between the electrical resistance measured using the DR-based NFMM and a four-point probe is 9.6%. Furthermore, the DR-based NFMM allows simultaneous imaging of topography and RF electrical conductivity of rough thick films without the need of an additional distance sensor; this ability is demonstrated for a rough CB028 thick film.
The 5GHz coaxial resonator transmission line-based NFMM employs a half-wavelength coaxial transmission line resonator terminated in a sharp tungsten tip as the microwave probe. A quartz-tuning fork based distance following feedback system is integrated with the microwave probe in order for the NFMM to operate in non-contact mode. The Q of the probe is degraded by 30% (Q=55) due to the presence of the quartz tuning fork. Despite the low Q, this NFMM is able to differentiate several insulating bulk samples (3.8 < E’r < 25) even if they are coated with an insulating layer of thickness similar to the apex radius of the tungsten tip. Finally, the coaxial resonator transmission line-based NFMM is able to image subsurface permittivity distribution of a flexible polymer-composite PDMS-Ba0.55Sr0.45TiO3 49% which is coated with 10 um thick parylene-C layer. Measurements performed at a tip-sample distance of 100 nm reveal that within an area of 50 um x 50 um, the relative permittivity of the polymer-composite is not constant but varies between 6.63 and 11.78.
4
Monti, Tamara. "Microwave microscopy and spectroscopy techniques with applications in nanotechnology and biology." Doctoral thesis, Università Politecnica delle Marche, 2014. http://hdl.handle.net/11566/242394.
Повний текст джерелаАнотація:
Un Microscopio a Scansione di sonda a Microonde e’ stato sviluppato e applicato in vari contesti. Esso lavora attraverso l’interazione di campo vicino a microonde tra una sonda emittente e il campione in analisi. La sua applicazione principale e’ la misura delle proprieta’ elettromagnetiche su scale estremamente piccole. Modelli con circuiti a parametri concentrati e distribuiti consentono di ottenere dati quantitativi dalle misure. Tali modelli diventano piu’ complessi se si considerano ambienti diversi. Questo e’ fondamentale per analizzare campioni biologici (in vitro o in vivo). Durante questo lavoro sono state fatte sia applicazioni a campioni biologici sia analisi “in-liquido”.
Un’ulteriore potenzialita’ del microscopio a microonde e’ la spettroscopia a livello atomico/molecolare. Uno degli argomenti di questa ricerca, affrontato presso la University of Maryland, e’ stato lo sviluppo di uno strumento, che lavorasse in ambiente criogenico, per la spettroscopia a microonde di materiali superconduttori ad alta temperature. La risoluzione atomica sarebbe stata utile per investigare i fenomeni non-lineari sulla nanoscala.
Un’ulteriore tematica e’ stata la detection di Risonanze di Spin Elettronico a microonde. Il microscopio e’ stato modificato per effettuare spettroscopie, con campioni immerse in flussi di campo magnetico.
Inoltre, un’esaustiva descrizione della risoluzione del microscopio e’ essenziale. Quindi, indagini riguardo la penetrazione “in-profondita’” del campo evanescente sono qui presentate. Questa capacita’ e’ estremamente interessante per ottenere una tomografia “a corto raggio” di campioni complessi (es.: cellule). E’ stata applicata una conversione nel dominio del tempo dei dati in frequenza a microonde.
Infine, il Microscopio a Scansione di sonda a Microonde e’ stato impiegato per creare pattern riproducibili sul grafene. Questo tipo di pattern e’ stato osservato sperimentalmente, e quindi e’ stato oggetto di studi teorici e numerici. Questa parte della ricerca e’ stata sviluppata in collaborazione con gli Oak Ridge National Laboratories che hanno fornito anche i campioni.A Scanning Microwave Microscope has been developed and applied within different contexts. It works through near-field microwave interaction between an emitting probe and a target sample. Its main application is the measurement, at extremely small scale, of electromagnetic features. Lumped and distributed circuit models allow getting quantitative data from measurements, although with limitations. Such models become even more complicated if considering different environments. This is fundamental for analyzing biological samples (in vitro or in vivo). During this work, both applications to biological samples and “in-liquid” analysis have been performed. Another potentiality of the microwave microscope is the spectroscopy at atomic/molecular level. One of the topics of this research, performed at University of Maryland, was the development of an instrument, working in cryogenic environment, for microwave spectroscopy of high-temperature superconductive materials. Atomic resolution would be useful in order to investigate non-linear phenomena at nanoscale. Another topic was the Electron Spin Resonance detection at microwave. The microscope has been modified in order to perform spectroscopy, with samples immersed in a magnetic field flux. Furthermore, the comprehensive description of the microscope resolution is essential. Then, investigations related to the “in-depth” penetration of the evanescent field are hereby presented. This capability is extremely interesting in order to get a “short-range” tomography of complex samples (e.g., cells). A “time-domain” conversion of the frequency microwave data has been applied. Finally, the Scanning Microwave Microscope has been employed in creating reproducible nanopatterns on graphene. This kind of pattening was observed experimentally, and then it was subject of theoretical and numerical investigation. This part of the research has been developed with Oak Ridge National Laboratories that provided the samples too.
5
Vitry, Pauline. "Applications and development of acoustic and microwave atomic force microscopy for high resolution tomography analysis." Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS046/document.
Повний текст джерелаАнотація:
La microscopie à force atomique (AFM) est un outil de caractérisation d’échantillons tant organiques qu’inorganiques d’intérêt en physique, en biologie et en métallurgie. Le champ d’investigation de la microscopie AFM reste néanmoins restreint à l’étude des propriétés surfaciques des échantillons et la caractérisation sub-surfacique à l’échelle nanométrique n’est pas envisageable au-delà de la nano-indentation. Lors de ce travail, nous nous sommes intéressés à deux techniques de sonde locale complémentaires pour l’investigation volumique haute résolution.La première technique proposée est la microscopie de champ proche ultrasonore (MS-AFM), mise en place et exploitée en collaboration avec Dr. L. Tétard de l’Université Centrale de Floride. Cette technique fournie des informations localisées en profondeur en utilisant des ondes acoustiques dans la gamme de fréquences du MHz. Une étude complète de l’influence des paramètres de fréquences a été réalisée sur des échantillons de calibration et a permis de valider un modèle d’interprétation numérique. Cette technique ultrasonore, non invasive, a été appliquée à la caractérisation de vésicules lipidiques au sein de bactéries lors d’une collaboration avec les Pr. A. Dazzi et M.-J. Virolle, de l’Université Paris Sud Orsay. Un couplage a été réalisé avec la microscopie AFM infra-rouge (AFM-IR). Cette étude a démontré le potentiel d’investigation et d’analyse volumique et chimique d’échantillons biologiques.La seconde technique étudiée est la microscopie micro-onde (SMM), développée en collaboration avec la société Keysight. Cette technique, tout comme la microscopie acoustique, est non invasive et conduit à une caractérisation physico-chimique basée sur l’interaction de micro-ondes (0.2-16 GHz) avec la matière. Dans le cas de métaux, un lien entre la fréquence et la profondeur d’investigation a été mis en évidence. Cette technique a été appliquée à l’étude de la diffusion d’élément chimique léger au sein de métaux et à la mesure des propriétés mécaniques des matériaux. L’ensemble de ces résultats ouvre un nouveau champ d’investigation de la tomographie 3D dans l’analyse volumique à l’échelle nanométrique que ce soit dans le domaine de la biologie ou de la métallurgieThe atomic force microscope (AFM) is a powerful tool for the characterization of organic and inorganic materials of interest in physics, biology and metallurgy. However, conventional scanning probe microscopy techniques are limited to the probing surface properties, while the subsurface analysis remains difficult beyond nanoindentation methods. Thus, the present thesis is focused on two novel complementary scanning probe techniques for high-resolution volumetric investigation that were develop to tackle this persisting challenge in nanometrology. The first technique considered, called Mode Synthesizing Atomic Force Microscopy (MSAFM), has been exploited in collaboration with Dr. Laurene Tetard of University of Central Florida to explore the volume of materials with high spatial resolution by means of mechanical actuation of the tip and the sample with acoustic waves of frequencies in the MHz range. A comprehensive study of the impact of the frequency parameters on the performance of subsurface imaging has been conducted through the use of calibrated samples and led to the validation of a numerical model for quantitative interpretation. Furthermore, this non-invasive technique has been utilized to locate lipid vesicles inside bacteria (in collaboration with Pr. A. Dazzi and M.-J. Virolle of Université Paris Sud, Orsay). Furthermore, we have combined this ultrasonic approach with infra-red microscopy, to add chemical speciation aimed at identifying the subsurface features, which represents a great advance for volume and chemical characterization of biological samples. The second technique considered is the Scanning Microwave Microscopy, which was developed in collaboration with Keysight society. Similar to acoustic-based microscopy, this non-invasive technique provided physical and chemical characterizations based on the interaction of micro-waves radiations with the matter (with frequency ranging from 0.2 and 16 GHz). Particularly, for metallic samples we performed volumetric characterization based on the skin effect of the materials. On the other hand, we have used this technique to analyze the diffusion of light chemical elements in metals and measured the effect of changes in mechanical properties of materials on their conductivity.Overall, these results constitute a new line of research involving non-destructive subsurface high resolution analysis by means of the AFM of great potential for several fields of research
6
Myers, Joshua Allen. "Nano-scale RF/Microwave Characterization of Materials' Electromagnetic Properties." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1340883872.
Повний текст джерела
7
Gu, Sijia. "Contribution to broadband local characterization of materials by near-field microwave microscopy." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10175/document.
Повний текст джерелаАнотація:
Les microscopes champ proche micro-ondes sont des instruments émergents pour la caractérisation de matériaux. Dans ce travail, un microscope champ proche micro-ondes fait maison est d'abord décrit et analysé en termes de résolution et de largeur de bande de fréquences de fonctionnement. Ensuite, il est mis en œuvre pour la caractérisation d'une grande variété de matériaux tels que par exemple des métaux, des semi-conducteurs, des diélectriques, des liquides et des nanomatériaux 2D. Le système intégre un interférométre pour améliorer la sensibilité de la mesure pour des fréquences de fonctionnement couvrant la bande 2-18 GHz. La sensibilité et les différents modes de fonctionnement disponibles (contact, sans contact, environnement liquide) permettent d'adresser une grande variété de domaines d'applications. La résolution latérale obtenue par cet instrument est plus petite de plusieurs ordres de grandeur que la longueur d'onde de fonctionnement, ouvrant ainsi la voie à une caractérisation locale. Les propriétés électromagnétiques des matériaux ont été extraites en utilisant la méthode de perturbation et celle de la ligne de transmission. En particulier, les propriétés diélectriques de solutions salines aqueuses et l’impédance complexe du graphène ont été étudiées dans une large bande de fréquence. Ce microscope champ proche micro-ondes basé sur une méthode interférométrique qui permet une analyse quantitative des propriétés des matériaux de manière non-destructive peut adresser un grand éventail d’applications dans de nombreux domaines scientifiques. Enfin, l’ensemble des résultats montre que potentiellement la microscopie champ proche micro-ondes dispose des atouts pour devenir un outil de métrologie important pour la caractérisation en micro- et nano-électroniqueNear-field microwave microscopes are emerging instruments for materials characterization. In this work, a home-made near-field microwave microscope is first described and analyzed in terms of resolution performance and frequency band of operation. Then, it is applied to the characterization of a large variety of materials such as metals, semiconductors, dielectrics, liquids and 2D nanomaterials. The system is based on an interferometric technique to improve the measurement sensitivity in the entire frequency range of operation spanning from 2 to 18 GHz. The sensitivity and the different operating modes available (contact, non-contact, liquid environment) allow addressing a large variety of application fields. The instrument allows a sub-wavelength lateral resolution which is more than two orders of magnitude smaller than the operating wavelength, opening the way to a local characterization. The cavity perturbation and transmission line approaches have been used to extract the electromagnetic properties of materials. In particular dielectric properties of saline aqueous solutions and complex impedance of graphene have been investigated in a broad frequency band. It provides a quantitative analysis of material properties in a non-destructive manner to address numerous applications in many scientific fields. Finally, all the results together show that the interferometer-based near-field microwave microscope has the potential to become an important metrology tool for characterizations in micro- and nano-electronics
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FABI, GIANLUCA. "Modelling and Experimental Characterization of new Microwave Microscopy Techniques for Quantitative Measurements." Doctoral thesis, Università Politecnica delle Marche, 2021. http://hdl.handle.net/11566/287825.
Повний текст джерелаАнотація:
Tecniche classiche di microscopia basate su interazioni in campo-lontano, come ad esempio il ben noto microscopio ottico tradizionale, hanno una risoluzione spaziale dell'ordine della lunghezza d'onda utilizzata. Perciò, se le dimensioni e le proprietà del campione variano in una scala di lunghezza minore della lunghezza d'onda, la risposta elettromagnetica del materiale è mediata su scale maggiori, e molti dettagli del campione vengono persi.
Il Microscopio a Scansione a Microonde in Campo-vicino (NFSMM o semplicemente SMM) ha superato questo paradigma con il concetto di interazione di campo-vicino tra una sonda (sorgente) ed il campione. In questo caso la sonda eccita il campione con un segnale a microonde e genera un campo evanescente focalizzato in un'area estremamente piccola del materiale. Il microscopio misura le proprietà del campione catturando il segnale di risposta generato da questa interazione, con una risoluzione determinata principalmente dalla dimensione della punta piuttosto che dalla lunghezza d'onda. Inoltre, l'SMM non solo misura strutture superficiali, ma anche proprietà elettromagnetiche fino ad alcuni micrometri sotto la superficie del campione, grazie alla profondità di penetrazione delle microonde.
Nonostante le interessanti possibilità ed applicazioni della tecnica, l'SMM presenta alcune limitazioni schematizzate di seguito:
1) banda e sensibilità limitata;
2) elevato numero di elementi parassiti;
3) ipersensibilità alla topografia del campione. Come conseguenza, molte proprietà elettromagnetiche del campione (oltre alla topografia) possono essere per la maggior parte invisibili nei dati acquisiti, poichè il contributo della topografia domina e nasconde questi effetti;
4) incompatibilità di utilizzo della tecnica in ambienti liquidi con perdite, come ad esempio all'interno di soluzioni saline. Questo rende l'utilizzo della tecnica estremamente complicata per applicazioni bio-compatibili, poichè il materiale biologico vivo è generalmente preservato all'interno di soluzioni fisiologiche per sopravvivere.
Di conseguenza, l'SMM è ampiamente utilizzato nello studio dei materiali semiconduttori o superfici inorganiche, ma presenta molte difficoltà per l'analisi di materiali rugosi e morbidi, come ad esempio cellule biologiche vive.
In questo contesto, il presente manoscritto illustra alcune soluzioni tecniche innovative, in particolare:
1) una nuova tecnica per la rimozione in tempo reale di effetti topografici indesiderati nelle immagini SMM. Il metodo ci ha permesso di rivelare proprietà elettromagnetiche dei materiali analizzati che erano inizialmente nascoste nei dati originali per via della ipersensibilità alla topografia del campione;
2) una nuova configurazione di microscopia chiamata microscopio a microonde invertito. Questo strumento presenta una banda migliorata e minor effetti parassiti rispetto a sistemi SMM convenzionali, permette l'analisi quantitativa delle proprietà elettromagnetiche dei campioni, ed è compatibile con l'ambiente fisiologico utilizzato per preservare materiale biologico vivo.
In quest'ottica, il presente documento riporta i principali risultati sperimentali delle metodologie e degli strumenti sviluppati, illustra i loro aspetti teorici e descrive il range di applicazioni delle tecniche proposte, includendo una discussione sulle direzioni future della ricerca.The Near-field Scanning Microwave Microscopy (NFSMM or simply SMM) employs the near-field interaction between a probe (source) and a sample to image and characterize materials with atomic resolution. In these systems, the probe excites the sample with microwave frequencies and generates a near-field focused in an extremely small area of the material surface. The microscope measures the local properties of the sample by collecting the response signal originated from this interaction, and the probe dimension mainly determines the resolution, rather than the excitation wavelength. Moreover, the SMM senses not only surface structures, but also electromagnetic properties up to a few micrometres below the sample surface, due to the microwave penetration. Despite the intriguing features and possible applications of the technique, the SMM presents some limitations summarized below: - limited bandwidth and sensitivity; - high number of parasitic components; - hypersensitivity to sample topography; As a consequence, many electromagnetic properties of the sample (beyond the sample topography) can be mostly invisible in SMM data, because the topographic contribution dominates and masks these effects. - incompatibility with the lossy liquid environment, such as inside saline solutions. This makes the application of SMM in bio-compatible environments highly challenging because live biological material is generally stored inside physiological solutions to survive. As a consequence, SMM is mainly limited to studies of semiconductor materials or inorganic surfaces, and it presents many difficulties for the analysis of non-flat and soft samples such as a living biological cell. In this context, the present manuscript illustrates some innovative technical solutions, in particular - a new technique for the real-time removal of unwanted topographic effects in SMM images. This method enabled us to reveal electromagnetic features of the material, that were hidden in the original data due to the hypersensitivity to sample topography; - a new microscope configuration called inverted Scanning Microwave Microscope. This setup has higher bandwidth and reduced parasitic components with respect to existing conventional SMM systems, it enables the local quantitative characterization of sample properties, and it is compatible with the physiological environment used to preserve live biological material. With this in mind, the present dissertation reports the main experimental results of the developed instruments and methodologies, illustrates their theoretical aspects, and discusses the range of applications of the proposed techniques, including the future directions of the research.
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Haenssler, Olaf Christian. "Multimodal sensing and imaging technology by integrated scanning electron, force, and near-field microwave microscopy and its application to submicrometer studies." Thesis, Lille, 2018. http://www.theses.fr/2018LIL1I006.
Повний текст джерелаАнотація:
La combinaison de plusieurs procédés d’imagerie et de mesure permet d’obtenir des ensembles de données complémentaires et parfois uniques. A l’aide d’une technique hybride de microscopie présentant des modalités de mesure différentes et des enregistrements synchrones, on peut recueillir des informations complémentaires sur des échantillons à l’échelle nanométrique. De plus, l’intégration de procédés nanorobotiques et de logiciels open-source permet une approche technologique pour la recherche sur les semi-conducteurs et les sciences des matériaux. Ce travail démontre le potentiel d’une telle technologie. Ce démonstrateur fonctionne dans la chambre d‘un MEB et sert de plateforme technologique dans laquelle sont intégrés différentes modalités, technologies et procédés. Un AFM basé sur un interféromètre optique compact permet l’imagerie de la topographie de surface tandis qu’un microscope à micro-ondes à balayage enregistre les caractéristiques électromagnétiques dans la gamme de fréquence des micro-ondes, le tout opérant dans le même MEB. L’engin est contrôlé par un ensemble de logiciels qui est optimisé pour la nanorobotique basée sur l‘imagerie. Ce démonstrateur technologique permet d’observer en direct la région d’intérêt à l’aide du microscope électronique tandis qu’est effectuée en champ proche la caractérisation de la surface de l’échantillon par intermédiaire des micro-ondes évanescentes et des forces intermoléculaires. Ensuite, est présenté un standard multimodal de test et qui valide la fonctionnalité de l’instrument démonstrateur. Le présent travail est complété par une analyse électrique de capacités MOS ainsi que leur approximation destinée au calibrageVarious disciplines of micro- and nanotechnology requires combinatorial tools for the investigation, manipulation and transport of materials in the submicrometer range. The coupling of multiple sensing and imaging techniques allows for obtaining complementary and often unique datasets of samples under test. By means of an integrated microscopy technique with different modalities, it is possible to gain multiple information about nanoscale samples by recording at the same time. The expansion with nanorobotics and an open-source software framework, leads to a technology approach for semiconductor research and material science. This work shows the potential of such a multimodal technology approach by focusing on a demonstrator setup. It operates under high-vacuum conditions inside the chamber of a Scanning Electron Microscope and serves as a technology platform by fusing various microscopy modalities, techniques and processes. An Atomic Force Microscope based on a compact, optical interferometer performs imaging of surface topography, and a Scanning Microwave Microscope records electromagnetic properties in the microwave frequency domain, both operating inside an SEM. A software framework controls the instrument. The setup allows for observing with SEM, while imaging and characterizing with interacting evanescent microwaves and intermolecular forces simultaneously. In addition, a multimodal test standard is introduced and subsequently confirms the functionality of the demonstrator. Within this context, the work also includes an electrical analysis of micro-scale MOS capacitors, including an approximation for use in the calibration
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Schlegel, Jennifer Lynn. "Imaging the spatial variation of dielectric constant in materials using microwave near field microscopy." Available to US Hopkins community, 2003. http://wwwlib.umi.com/dissertations/dlnow/3080759.
Повний текст джерела
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Ross, Anthony J. III. "Laser Machining and Near Field Microwave Microscopy of Silver Inks for 3D Printable RF Devices." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6944.
Повний текст джерелаАнотація:
3D printable materials for RF devices need improvement in order to satisfy the demand for higher frequency and lower loss performance. Characterization of materials that have shown improvements of conductor conductivity have been performed. By using a laser machining technique the loss of a 3D printed 2.45 GHz microstrip Square Open Loop Resonator (SOLR) bandpass filter has been shown to improve by 2.1dB, along with an increase in bandwidth from 10% to 12.7% when compared to a SOLR filter that has not been laser machined. Both laser machined and microwaved silver inks have been mapped for conductivity using a Near Field Microwave Microscope (NFMM) and have shown improvement of conductivity compared to inks that have been cured using standard methods.
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Tholén, Erik. "Intermodulation in microresonators : for microwave amplification and nanoscale surface analysis." Doctoral thesis, KTH, Nanostrukturfysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11593.
Повний текст джерелаАнотація:
This work explores the effects of weak nonlinearity on harmonic oscillators.Two particular systems are studied experimentally: A superconductingresonator formed from a coplanar waveguide that oscillates at microwave frequencies,and the cantilever of an atomic force microscope (AFM) vibratingat ultrasonic frequencies. Both of these systems are described in the introduction,followed by a theory chapter giving a general theoretical framework for nonlinear oscillators. Basic properties of nonlinear oscillators, such asbifurcation and intermodulation, are explained using simple models. Experimental methods, including cryogenic and microwave measurement techniques,are described in some detail. The nonlinear superconducting resonator is studied for use as a parametric amplifier. A strong drive tone, called the pump, drives the oscillator nearthe point of bifurcation. A second, much weaker drive signal that is slightlydetuned from the pump, will cause energy to move from the pump to the signal, giving signal amplification. We have measured a signal gain greaterthan 22 dB in a bandwidth of 30 kHz, for a resonator pumped at 7.6 GHz.This type of amplifier is phase-sensitive, meaning that signals in phase withthe pump will be amplified, but signals in quadrature phase of the pump will be deamplified. Phase-sensitivity has important implications on the amplifier’snoise properties. With a parametric amplifier, a signal can be amplified without any additional noise being added by the amplifier, something that is fundamentally impossible for a standard amplifier. The vibrating AFM cantilever becomes a nonlinear oscillator when it is interacting with a surface. When driven with two frequencies, the amplitudeand phase of the cantilever’s response will develop mixing products, or intermodulation products, that are very sensitive to the exact form of the nonlinearity. Very small changes in the surface properties will be detectable when measuring the intermodulation products. Simultaneously measuring many intermodulation products, or acquiring an intermodulation spectrum,allows one to reconstruct the tip-surface interaction. Intermodulation AFM increases the sensitivity of the measurement or the contrast of the acquiredimages, and provides a means of rapidly measuring the nonlinear tip-surface interaction. The method promises to enhance the functionality of the AFM beyond simple topography measurement, towards quantitative analysis of the chemical or material properties of the surface.QC 20100812
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Рибалко, Олександр Олександрович, Александр Александрович Рыбалко, Oleksandr Oleksandrovych Rybalko та А. А. Кобрик. "Применение микроволновой сканирующей микроскопии в производстве нанокомпонент". Thesis, Сумский государственный университет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/43872.
Повний текст джерелаАнотація:
Сканирующая микроволновая микроскопия (СММ) относится к современному направлению экспериментальных исследований материалов и объектов с наноразмерной разрешающей способностью. Наибольшее развитие СММ достигла в области диагностики высокотемпературных полупроводниковых материалов и структур.
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An, Zhong. "Interpretation of X-ray and microwave images : some transform methods and phase unwrapping." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313792.
Повний текст джерела
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Ben, Mbarek Sofiane. "Etude et réalisation d’antennes à concentration de champ pour la génération et la détection locale de champs électromagnétiques." Thesis, Besançon, 2011. http://www.theses.fr/2011BESA2018.
Повний текст джерелаАнотація:
L’objectif de cette thèse est le développement des détecteurs pour la microscopie champproche électromagnétique pour deux domaines fréquentiels. Pour le domaine des microondesnous présentons des micro-antennes non conventionnelles basées sur un guidagecoplanaire et l’effet de pointe. Nous pr´esentons les différentes étapes de la conceptionet de la réalisation avec les techniques de micro-fabrication. L’évaluation de leur performancea été obtenue avec une confrontation des résultats de mesure et de cartographie surdes éléments passifs et ceux d’une modélisation d’intégration finie. Pour le domaine desTérahertz, nous avons réalisé des micro-bolométres à température ambiante. Dans le butd’améliorer l’absorption de ces d´etecteurs, leur conception a été basée sur l’étude théoriquede l’absorption d’une onde électromagnétique en incidence normale sur un empilement descouches métalliques et diélectrique. Deux versions ont été réalisées et caractérisées é l’aidedes sources électroniques qui peuvent atteindre 1, 1 THz en continue. Les performancesde ces d´etecteurs en termes de bruit, de sensibilit´e et de temps de r´eponse sont mises enexergueThe objective of this thesis is the development of detectors for near-field microscopy fortwo electromagnetic frequency domains. For microwave domain we present unconventionalmicro-antennas based on coplanar line and point effect. We present the different stages ofthe design and implementation with micro-fabrication technique. The evaluation of theirperformance was obtained with a comparison of measurement results and mapping ofpassive elements and those of a model of finite integration. For the THz domain, we performedroom temperature micro-bolometers. In order to improve the absorption of thesedetectors, their design was based on the theoretical study of the absorption of an electromagneticwave normally incident on a stack of metal and dielectric layers. Two versionswere prepared and characterized using electronic sources that can reach continuous 1,1THz. The performance of these detectors in terms of noise, sensitivity and time responseare highlighted
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Huang, Jian Hui. "The applications of microwave energy to improve grindability and extraction of gold ores." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369344.
Повний текст джерелаАнотація:
Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir gold ore, in which gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37-39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.581.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional heating environment was also investigated.I,n a nitric acid solution, pyrite and marcasite can be rapidly leached. Reaction temperature and the concentration of HNO3 had a significant influence on decomposition rate. Marcasite had a substantially higher i decomposition rate than pyrite. Microwave heating could promote the dissociation of marcasite and pyrite, compared with conventional heating. This was caused by special volumetric heating during microwave exposure that may induce local overheating or improve the interactions between the high dielectric loss minerals and the leaching solution. Kinetic investigations show that the decomposition of both the minerals in a nitric acid medium is controlled by chemical reactions on the surfaces of particles. The decomposition is a second order reaction with respect to nitric acid concentration. Less than 5- 7% of the decomposed sulphur was transformed into elemental sulphur during the leaching of both the minerals
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Eklund, Anders. "Microwave Frequency Stability and Spin Wave Mode Structure in Nano-Contact Spin Torque Oscillators." Doctoral thesis, KTH, Integrerade komponenter och kretsar, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188546.
Повний текст джерелаАнотація:
The nano-contact spin torque oscillator (NC-STO) is an emerging device for highly tunable microwave frequency generation in the range from 0.1 GHz to above 65 GHz with an on-chip footprint on the scale of a few μm. The frequency is inherent to the magnetic material of the NC-STO and is excited by an electrical DC current by means of the spin torque transfer effect. Although the general operation is well understood, more detailed aspects such as a generally nonlinear frequency versus current relationship, mode-jumping and high device-to-device variability represent open questions. Further application-oriented questions are related to increasing the electrical output power through synchronization of multiple NC-STOs and integration with CMOS integrated circuits. This thesis consists of an experimental part and a simulation part. Experimentally, for the frequency stability it is found that the slow but strong 1/f-type frequency fluctuations are related to the degree of nonlinearity and the presence of perturbing, unexcited modes. It is also found that the NC-STO can exhibit up to three propagating spin wave oscillation modes with different frequencies and can randomly jump between them. These findings were made possible through the development of a specialized microwave time-domain measurement circuit. Another instrumental achievement was made with synchrotron X-rays, where we image dynamically the magnetic internals of an operating NC-STO device and reveal a spin wave mode structure with a complexity significantly higher than the one predicted by the present theory. In the simulations, we are able to reproduce the nonlinear current dependence by including spin wave-reflecting barriers in the nm-thick metallic, magnetic free layer. A physical model for the barriers is introduced in the form of metal grain boundaries with reduced magnetic exchange coupling. Using the experimentally measured average grain size of 30 nm, the spin wave mode structure resulting from the grain model is able to reproduce the experimentally found device nonlinearity and high device-to-device variability. In conclusion, the results point out microscopic material grains in the metallic free layer as the reason behind the nonlinear frequency versus current behavior and multiple propagating spin wave modes and thereby as a source of device-to-device variability and frequency instability.Dagens snabba utveckling inom informationsteknik drivs på av ständigt växande informationsmängder och deras samhällsanvändning inom allt från resursoptimering till underhållning. Utvecklingen möjliggörs till stor del hårdvarumässigt av miniatyrisering och integrering av elektroniska komponenter samt trådlös kommunikation med allt större bandbredd och högre överföringshastighet. Det senare uppnås främst genom utnyttjande av högre radiofrekvenser i teknologiskt tidigare oåtkomliga delar av spektrumet. Frekvensutnyttjandet har det senaste årtiondet ökat markant i mikrovågsområdet med typiska frekvenser runt 2.4 GHz och 5.2-5.8 GHz. I den spinntroniska oscillatorn (STO:n) möjliggörs frekvensgenerering i det breda området från 0.1 GHz upp till över 65 GHz av en komponent med mikrometerstorlek som kan integreras direkt i CMOS-mikrochip. Till skillnad från i konventionella radiokretsar med oscillatorer konstruerade av integrerade transistorer och spolar, genereras mikrovågsfrekvensen direkt i STO:ns magnetiska material och omvandlas därefter till en elektrisk signal genom komponentens magnetoresistans. Dessa materialegenskaper möjliggör ett tillgängligt frekvensband med extrem bredd i en och samma STO, som därtill kan frekvensmoduleras direkt genom sin styrström och på så sätt förenklar konstruktionen av sändarsystem. STO:ns icke-linjära egenskaper kan potentiellt också användas för att i en och samma komponent blanda ned mottagna mikrovågssignaler och på så sätt förenkla konstruktionen även av mikrovågsmottagare. STO:ns signalegenskaper bestäms av det magnetiska materialets fysik i form av magnetiseringsdynamik driven av elektriskt genererade spinnströmmar. I denna avhandling studeras denna dynamik experimentellt med särskilt fokus på frekvensstabiliteten i den hittills mest stabila STO-typen; nanokontakts-STO:n. Genom mätningar i tidsdomän av STO:ns elektriska signaler runt 25 GHz har frekvensstabiliteten funnits hänga samman med den typ av icke-linjärt beteende som också funnits vara utmärkande för tillverkningsvariationen i komponenterna. Mikroskopiska undersökningar av materialet visar att en trolig källa till denna variation är den magnetiska metallens uppbyggnad i form av korn i storleksordningen 30 nm, och datorsimuleringar av en sådan materialstruktur har visats kunna reproducera de experimentella resultaten. Därtill har en metod utvecklats för att med röntgenstrålning direkt mäta de små, magnetiska mikrovågsrörelserna i materialet. Denna röntgenteknik möjliggör detaljerade experimentella studier av magnetiseringsdynamiken och kan användas för att verifiera och vidareutveckla den existerande teorin för mikrovågsspinntronik. Sammantaget förs STO-teknologin genom denna studie ett steg närmare sina tänkbara samhällsbreda tillämpningar inom snabb, trådlös kommunikation för massproducerade produkter med integrerad sensor- och datorfunktionalitet.
QC 20160620
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Chipaux, Mayeul. "Ensembles de centres azote-lacune du diamant pour la cartographie de champs magnétiques à l'échelle microscopique et l'analyse de spectres de signaux dans le domaine hyperfréquence." Thesis, Cachan, Ecole normale supérieure, 2014. http://www.theses.fr/2014DENS0057/document.
Повний текст джерелаАнотація:
Le centre coloré azote-lacune du diamant, appelé centre NV, est comparable à un atome piégé à l’état solide. Ses propriétés de spin, conservées à température ambiante, permettent la détection de résonances magnétiques par voie purement optique. Le travail décrit dans cette thèse est centré sur l’utilisation d’ensembles de centres NV pour répondre à des problématiques à la fois scientifiques et industrielles. Nous avons réalisé un microscope de photoluminescence permettant d’exploiter les propriétés d’une couche nanométrique de centres NV. Les images obtenues ont une résolution spatiale de 500 nm et les fluctuations du signal sont limitées par le bruit de photons. En soumettant les centres NV à un signal hyperfréquence connu, nous pouvons reconstituer la cartographie à l’échelle microscopique des trois composantes d’espace d’un champ magnétique : par exemple, celui produit par un conducteur parcouru par un courant. La sensibilité associée à une surface d’intégration de 1 µm² de la couche de centres NV est de l’ordre du microtesla par racine de hertz. Notre dispositif d’imagerie permet également d’analyser le spectre d’un signal hyperfréquence. En soumettant les centres NV à un gradient de champ magnétique connu, l’information spectrale est transformée en information spatiale. Des résultats préliminaires montrent l’analyse simultanée d’une bande de fréquences de 700 MHz associée à une résolution de 7 MHz et à un taux de rafraîchissement de 4 ms. Ces travaux illustrent les perspectives prometteuses du centre NV du diamant, notamment pour le contrôle de circuits électroniques et l’analyse en temps réel de spectres hyperfréquences pris dans leur ensembleThe nitrogen-vacancy color center of diamond, called NV center, is an atom like system trapped in a solid lattice. Its spin properties, kept at room temperature, allow the detection of magnetic resonances by purely optical means. The work described in this thesis is focused on the use of NV centers’ ensembles targeting both scientific and industrial issues. We realized a photoluminescence microscope that exploits the properties of a nanoscale layer of NV centers. The spatial resolution of the resulting image is around 500 nm and the fluctuations of the signal is limited by the shot-noise. When the NV centers are submitted to a microwave signal witch frequency is known, the cartography of the three spatial components of the magnetic field, the one produced by a conductor carrying a current for example, can be determined at the microscopic scale. The sensitivity associated to an integration surface on the NV center layer of 1 µm² is in the order of the microtesla per square root of hertz. Our imaging device also leads to the spectral analysis of a microwave signal. When the NV centers are submitted to a known magnetic field gradient, the spectral information is transformed into spatial information. Preliminary results show the simultaneous analysis of a 700 MHz frequency band associated to a resolution of 7 MHz and a refresh rate of 4 ms. These works illustrate promising perspectives for the NV center of diamond, especially for the control of electronic circuits and the real time analysis of a whole microwave spectrum
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Fong, Kin Chung. "High Sensitivity Electron Spin Resonance by Magnetic Resonance Force Microscopy at Low Temperature." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1228338129.
Повний текст джерела
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Barutcu, Mazi Isil. "Effects Of Different Batter Formulations On Physical And Chemical Properties Of Microwave And Conventionally Fried Chicken Fingers." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611495/index.pdf.
Повний текст джерелаАнотація:
The main objective of this study was to determine the effects of batters containing various flour types and frying methods on physical and chemical properties of chicken fingers.
To determine the effects of different flour types, 30 % of the corn and wheat flour mix in control batter was replaced with chickpea, rice or soy flours. Frying was performed in microwave oven at 365 W (70 %) power level and at 180
1°
C for different times. Samples were also fried in a conventional fryer at 180&
#61617
1°
C for comparison. The properties that were measured were coating pick-up and moisture content, oil content, color, hardness, porosity and acrylamide content of fried samples. In addition, microstructural analysis of batters and temperature distribution of fried samples during cooling were performed. Moisture content of chicken fingers decreased whereas the darkness, porosity and hardness of samples increased with increasing microwave frying time. Using microwaves decreased frying time by 70 %. Samples fried for 1.5 min using microwave provided similar moisture and oil contents in the coating part as compared to conventionally fried ones for 5min. However, the chicken part of microwave fried sample had lower moisture content. Lighter colored samples with higher porosity and lower hardness values were obtained with microwave frying. In microwave frying, soy flour addition to batter formulation decreased the moisture loss and oil absorption as compared to control by 19.3% and 20.7%, respectively. The lowest hardness, the highest porosity and oil content were obtained with the addition of chickpea flour. Flour type was not found to be effective on acrylamide content. Microwave frying provided lower acrylamide content as compared to those fried conventionally for all types of flours. The reduction in acrylamide level was the highest (34.5%) for rice flour containing batter. Color parameters of chicken fingers were not found to be a reliable indicator of acrylamide levels. Different types of frying method and flours used in batter formulation resulted in differences in the microstructure of fried batter. Variations in internal temperature distribution during cooling increased with frying time in both microwave and conventional frying. The sample fried in microwave oven for 1.5 min had a more nonuniform temperature distribution.
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Tranquilin, Ricardo Luis [UNESP]. "Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/88504.
Повний текст джерелаАнотація:
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tranquilin_rl_me_bauru.pdf: 1401003 bytes, checksum: 671b0d9181df24fb0ba937b77bcac1d8 (MD5)O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência.
The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence.
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Hänßler, Olaf C. [Verfasser], Didier [Akademischer Betreuer] Théron, and Sergej [Akademischer Betreuer] Fatikow. "Multimodal sensing and imaging technology by integrated scanning electron, force, and nearfield microwave microscopy and its application to submicrometer studies / Olaf C. Hänßler ; Didier Théron, Sergej Fatikow." Oldenburg : BIS der Universität Oldenburg, 2018. http://d-nb.info/1157010199/34.
Повний текст джерела
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Hänßler, Olaf C. Verfasser], Didier [Akademischer Betreuer] Théron, and Sergej [Akademischer Betreuer] [Fatikow. "Multimodal sensing and imaging technology by integrated scanning electron, force, and nearfield microwave microscopy and its application to submicrometer studies / Olaf C. Hänßler ; Didier Théron, Sergej Fatikow." Oldenburg : BIS der Universität Oldenburg, 2018. http://d-nb.info/1157010199/34.
Повний текст джерела
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RAMBO, CARLOS R. "Obtenção de sílica e carbeto de silício a partir da exposição da palha de arroz a microondas e a campos eletromagnéticos na faixa de r.f." reponame:Repositório Institucional do IPEN, 1997. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10676.
Повний текст джерелаАнотація:
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Brown, Treva T. "Fabrication and Characterization of Intricate Nanostructures." ScholarWorks@UNO, 2017. https://scholarworks.uno.edu/td/2399.
Повний текст джерелаАнотація:
Encapsulation of nanoparticles within hexaniobate nanoscrolls presents interesting advances in the formation of nanocomposites exhibiting unique multi-dimensional properties. Building upon previous successes, facile yet versatile wet-chemical and microwave-irradiation synthetic protocols for the fabrication of a series of hexaniobate composites are presented herein. Solvothermal and, more recently, microwave-assisted methods have been developed that allow for the fabrication of peapod-like structures. During solvothermal treatment, exfoliated hexaniobate nanosheets scroll around highly ordered chains of preformed nanoparticles (NPs) to produce nanopeapods (NPPs). This approach offers versatility and high yields, in addition to the potential for advanced functional device fabrication.
For the characterization of these materials, advanced techniques in atomic force microscopy (AFM) were used for investigating the surface of materials at the nanometer scale. Extensive physical, dynamic, and force modulation studies were performed on novel oxide nanocomposites by implementing particular scanning techniques to determine information such as topology, stress-induced behavior at the nanoscale, magnetic behavior, and frictional forces of the nanoscale materials. These composites were then analyzed by topological intermittent contact studies in tapping and contact mode, as well as with derivative techniques of these commonly used scanning probe approaches.
In addition to studying surfaces using conventional modes of AFM, the mechanical properties of these nanocomposites were measured via dynamic lateral force modulation (DLFM) and magnetic properties of functionalized magnetic nanosheets were mapped via magnetic sampling modulation (MSM). By utilizing the capabilities of the DLFM imaging mode, elastic properties such as Young’s Modulus were measured from force-distance curves. In addition to this modulation mode, MSM was used to selectively map the vibrating magnetic nanomaterials from a modulated electromagnetic field. The information obtained from these AFM techniques can be helpful in determining the relative structural behavior of these nanocomposites and gauge their use in various applications such as structural engineering of nanoarchitectures as well as studying magnetic characteristics of metal oxide nanocomposites that exhibit characteristics different from their bulk counterparts.
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Tranquilin, Ricardo Luis. "Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas /." Bauru : [s.n], 2009. http://hdl.handle.net/11449/88504.
Повний текст джерелаАнотація:
Orientador: Élson LongoBanca: Fenelon Martinho Lima Pontes
Banca: Alberthmeiry Teixeira Figueiredo
- O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp
Resumo: O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência.
Abstract: The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence.
Mestre
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Moreno, Villavicencio Maiglid Andreina. "Development of 3D high-resolution imaging of complex devices by the correlation of ToF-SIMS and AFM." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI122.
Повний текст джерелаАнотація:
La miniaturisation continue et la complexité des dispositifs poussent les techniques existantes de nano-caractérisation à leurs limites. De ce fait, la combinaison de ces techniques apparait être une solution attrayante pour continuer à fournir une caractérisation précise et exacte. Dans le but de dépasser les verrous existants pour l’imagerie chimique 3D haute résolution à l’échelle nanométrique, nous avons concentré nos recherches sur la création d’un protocole combinant la spectrométrie de masse à ions secondaires de temps de vol (ToF-SIMS) avec la microscopie à force atomique (AFM). Ceci permet entre autre de corréler la composition et la visualisation en 3 dimensions avec des cartographies de topographie ou d’autres propriétés locales fournies par l’AFM. Trois principaux résultats sont obtenus grâce à cette méthodologie : la correction d’un ensemble de données ToF-SIMS pour une visualisation 3D sans artefacts, la cartographie du taux de pulvérisation locale permettant de mettre en évidence les effets liés à la rugosité et la présence d’interfaces verticales et la superposition des informations avancées ToF-SIMS et AFM. Quatre applications de la méthodologie combinée ToF-SIMS et AFM sont abordées dans cette thèse. La procédure de correction des données ToF-SIMS en 3D a été appliquée sur une structure hétérogène GaAs / SiO2. Les artefacts liés à la pulvérisation, notamment l’effet d’ombrage, ont été étudiés par le biais des cartographies de taux de pulvérisation sur des échantillons avec nano-motifs structurés et non structuré. Enfin, nous avons exploré la combinaison de l’analyse ToF-SIMS avec trois modes avancées de microscopie AFM : piézoélectrique (PFM), capacité (SCM) et conducteur (SSRM). Une première étude a notamment permis d’observer l’évolution et la modification chimique suite à l’application d’une contrainte électrique sur deux film mince piézoélectriques. Une deuxième étude s’est focalisée sur l’impact de l’implantation Ga lors de la préparation d’échantillons par FIB pour voir comment limiter l’effet de l’amorphisation sur la mesure électrique. Les aspects techniques de la méthodologie seront abordés pour chacune de ces applications et les perspectives de cette combinaison seront discutésThe continuous miniaturization and complexity of devices have pushed existing nano-characterization techniques to their limits. The correlation of techniques has then become an attractive solution to keep providing precise and accurate characterization. With the aim of overcoming the existing barriers for the 3D high-resolution imaging at the nanoscale, we have focused our research on creating a protocol to combine time-of-flight secondary ion mass spectrometry (ToF-SIMS) with atomic force microscopy (AFM). This combination permits the correlation of the composition in 3-dimensions with the maps of topography and other local properties provided by the AFM. Three main results are achieved through this methodology: a topography-corrected 3D ToF-SIMS data set, maps of local sputter rate where the effect of roughness and vertical interfaces are seen and overlays of the ToF-SIMS and AFM advanced information. The application fields of the ToF-SIMS and AFM combined methodology can be larger than expected. Indeed, four different applications are discussed in this thesis. The procedure to obtain the topography-corrected 3D data sets was applied on a GaAs / SiO2 patterned structure whose initial topography and composition with materials of different sputter rates create a distortion in the classical 3D chemical visualization. The protocol to generate sputter rate maps was used on samples with structured and non-structured nano-areas in order to study the possible ToF-SIMS sputtering artefacts, especially the geometric shadowing effect. Finally, we have explored the combination of ToF-SIMS analysis with three AFM advanced modes: piezoresponse force microcopy (PFM), scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM). Specifically, two main applications were studied: the chemical modification during electrical stress of a piezoelectic thin film and the recovery of initial electrical characteristics of a sample subjected to Ga implantation during FIB preparation. Technical aspects of the methodology will be discussed for each application and the perspectives of this combination will be given
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PINHEIRO, LUCAS B. "Síntese e caracterização de compósitos de NiO-YSZ-CeOsub(2) com tratamento hidrotermal assistido por micro-ondas." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10574.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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ISIDORO, ROBERTA A. "Desenvolvimento de eletrocatalisadores de PdM (M= Ni, Cu, Ag) para reação de redução de oxigênio em meio básico na ausência e presença de álcool." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26388.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-06-22T13:42:56Z
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Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Lin, Tianjun. "Investigation of microwave imaging and local dielectric characterization of materials by using a homemade interferometer-based near-field microwave microscope." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1I016/document.
Повний текст джерелаАнотація:
La microscopie champ proche micro-onde, qui fait partie de la famille des microscopies à sonde locale, est envisagée aujourd’hui dans de nombreux domaines d’applications de la physique, de la biologie et des micro et nanotechnologies. Dans ce manuscrit, le microscope micro-onde à champ proche qui est exploité est un instrument développé au laboratoire IEMN bénéficiant d’une grande sensibilité dans une large bande de fréquences de travail [2-18 GHz]. Le potentiel d’applications du microscope est démontré au travers de la caractérisation de liquides avec différentes modalités de caractérisation (sonde en contact, sans contact et en immersion). En particulier, cet outil est mis en œuvre pour la spectroscopie diélectrique de solutions aqueuses de glucose.Cet instrument qui offre une capacité d'imagerie sub-longueur d'onde est également testé pour différentes situations (imagerie de surface et de sub-surface). La résolution d'imagerie ainsi que la précision de mesure sont évaluées puis des méthodes de traitement d'images simples sont proposées pour améliorer la qualité de l'imagerie. Enfin, une piste pour une intégration plus grande de l’instrument, qui consisterait à remplacer l’analyseur de réseau par un dispositif plus compact (type réflectomètre six-ports) est exploréeNear-field microwave microscopes, which belong to the local scanning probe microscopes family, are considered today as advanced characterization tools in many applications areas including physics, biology and micro and nanotechnologies. The near-field microwave microscope that is used in the work and described in this manuscript is an instrument developed at IEMN owning a great sensitivity in a wide operating frequency band [2-18 GHz]. The potential of the microscope in terms of applications is demonstrated through the characterization of liquids with different modalities of characterization (probe in contact, non-contact and immersed in a liquid). In particular, this instrument is investigated for dielectric spectroscopy of aqueous glucose solutions.This characterization tool that offers sub-wavelength imaging capability is also tested in different situations (surface and subsurface imaging). Imaging resolution and measurement accuracy are evaluated and easily implementable processing methods are proposed to improve the quality of imaging. Finally, a solution towards a larger compactness of the instrument is investigated through the replacement of the network analyzer by a more compact device (six-port reflectometer type)
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Imtiaz, Atif. "Quantitative materials contrast at high spatial resolution with a novel near-field scanning microwave microscope." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2469.
Повний текст джерелаАнотація:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Myers, Joshua. "NANO-MATERIALS FOR MICROWAVE AND TERAHERTZ APPLICATIONS." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1450358356.
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Hengst, Claudia. "Magnetisierungsdynamik weichmagnetischer Dünnschichten mit modifizierter magnetischer Mikrostruktur." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-134828.
Повний текст джерелаАнотація:
Abschlussdomänenstrukturen in strukturierten weichmagnetischen dünnen Schichten wurden systematisch hinsichtlich ihrer Domänenweite, Domänenmagnetisierungsrichtung, Domänenwandtypen und Wandlängen modifiziert. Somit konnte ein umfassendes Verständnis über die Beeinflussungsmöglichkeiten des dynamischen Magnetisierungsverhaltens von Abschlussdomänenkonfigurationen im GHz-Bereich erarbeitet werden. Ein bekanntes Modell zur Berechnung der akustischen Domänenresonanzfrequenz von 180° -Domänenkonfigurationen wurde unter Berücksichtigung von Abschlussdomänen und endlichen effektiven Domänenwandweiten erfolgreich erweitert. Damit ist eine präzise Vorhersage des dynamischen Verhaltens von 180° - Abschlussdomänenstrukturen möglich.
Außerdem wurde aufgezeigt, dass über die Messung der ferromagnetischen Resonanz Domänenwandumwandlungen im Magnetfeld detektiert werden können. Für Strukturen mit angepasster Anisotropie wurde unabhängig von der Anisotropiestärke eine konstante akustische Resonanzfrequenz beobachtet. Dieser unerwartete Zusammenhang wird auf die kompensatorischeWirkung von Abschlussdomänenstrukturen zurückgeführt. Abschließend wird gezeigt, dass für sogenannte Bucklingdomänenstrukturen eine signifikant größere Beeinflussung der ferromagnetischen Resonanzfrequenz durch vergleichsweise kleine statische Magnetfelder erzielt werden kann, als dies bei homogen magnetisierten Strukturen und Schichten der Fall ist. Die vorgestellten Ergebnisse dieser Arbeit zeigen, dass über eine Einstellung der ferromagnetischen Domänenstruktur das dynamische Verhalten weichmagnetischer strukturierter Schichten über einen vergleichsweise breiten Frequenzbereich hinweg gezielt modifiziert werden kann.
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Rapoport, Daniel Hans. "Rastersondenmikroskopie mit Hochfrequenzsignalen." Doctoral thesis, [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963020196.
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Hamadeh, Abbass. "Synchronization of spin trasnsfer nano-oscillators." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112262/document.
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Les nano-Oscillateurs à transfert de spin (STNOs) sont des dispositifs capables d'émettre une onde hyperfréquence lorsqu'ils sont pompés par un courant polarisé grâce au couple de transfert de spin. Bien qu'ils offrent de nombreux avantages (agilité spectrale, intégrabilité, etc.) pour les applications, leur puissance d'émission et leur pureté spectrale sont en général faibles. Une stratégie pour améliorer ces propriétés est de synchroniser plusieurs oscillateurs entre eux. Une première étape est de comprendre la synchronisation d'un STNO unique à une source externe. Pour cela, nous avons étudié une vanne de spin Cu60|NiFe15|Cu10|NiFe4| Au25 (épaisseurs en nm) de section circulaire de 200 nm. Dans l'état saturé perpendiculaire (champ appliqué > 0.8 T), nous avons déterminé la nature du mode qui auto-Oscille et son couplage à une source externe grâce à un microscope de force par résonance magnétique (MRFM). Seul un champ micro-Onde uniforme permet de synchroniser le mode oscillant de la couche fine car il possède la bonne symétrie spatiale, au contraire du courant micro-Onde traversant l'échantillon. Ce même échantillon a ensuite été étudié sous faible champ perpendiculaire, les deux couches magnétiques étant alors dans l'état vortex. Dans ce cas, il est possible d'exciter un mode de grande cohérence (F/ ∆F >15000) avec une largeur de raie inférieure à 100 kHz. En analysant le contenu harmonique du spectre, nous avons déterminé que le couplage non-Linéaire amplitude-Phase du mode excité est quasi nul, ce qui explique la grande pureté spectrale observée, et qu'en parallèle, la fréquence d'oscillation reste ajustable sur une grande gamme grâce au champ d'Oersted créé par le courant injecté. De plus, la synchronisation de ce mode à une source de champ micro-Onde est très robuste, la largeur de raie mesurée diminuant de plus de cinq ordres de grandeur par rapport au régime autonome. Nous concluons de cette étude que le couplage magnéto-Dipolaire entre STNOs à base de vortex est très prometteur pour obtenir une synchronisation mutuelle, le champ dipolaire rayonné par un STNO sur ses voisins jouant alors le rôle de la source micro-Onde. Nous sommes donc passés à l'étape suivante, à savoir la mesure expérimentale de deux STNOs similaires séparés latéralement de 100 nm. En jouant sur les différentes configurations de polarités des vortex, nous avons réussi à observer la synchronisation mutuelle de ces deux oscillateursSpin transfer nano-Oscillators (STNOs) are nanoscale devices capable of generating high frequency microwave signals through spin momentum transfer. Although they offer decisive advantages compared to existing technology (spectral agility, integrability, etc.), their emitted power and spectral purity are quite poor. In view of their applications, a promising strategy to improve the coherence and increase the emitted microwave power of these devices is to mutually synchronize several of them. A first step is to understand the synchronization of a single STNO to an external source. For this, we have studied a circular nanopillar of diameter 200~nm patterned from a Cu60|Py15|Cu10|Py4|Au25 stack, where thicknesses are in nm. In the saturated state (bias magnetic field > 0.8 T), we have identified the auto-Oscillating mode and its coupling to an external source by using a magnetic resonance force microscope (MRFM). Only the uniform microwave field applied perpendicularly to the bias field is efficient to synchronize the STNO because it shares the spatial symmetry of the auto-Oscillation mode, in contrast to the microwave current passing through the device. The same sample was then studied under low perpendicular magnetic field, with the two magnetic layers in the vortex state. In this case, it is possible to excite a highly coherent mode (F/∆F>15000) with a linewidth below 100 kHz. By analyzing the harmonic content of the spectrum, we have determined that the non-Linear amplitude-Phase coupling of the excited mode is almost vanishing, which explains the high spectral purity observed. Moreover, the oscillation frequency can still be widely tuned thanks to the Oersted field created by the dc current. We have also shown that the synchronization of this mode to a microwave field source is very robust, the generation linewidth decreasing by more than five orders of magnitude compared to the autonomous regime. From these findings we conclude that the magneto-Dipolar interaction is promising to achieve mutual coupling of vortex based STNOs, the dipolar field from a neighboring oscillator playing the role of the microwave source. We have thus experimentally measured a system composed of two STNOs laterally separated by 100 nm. By varying the different configurations of vortex polarities, we have observed the mutual synchronization of these two oscillators
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Zill-e-Huma, Huma. "Hydrodiffusion assistée par micro-ondes : nouvelle technique d'éco-extraction." Thesis, Avignon, 2010. http://www.theses.fr/2010AVIG0239/document.
Повний текст джерелаАнотація:
Microwave hydrodiffusion and gravity (MHG) technique is an attempt towards development of green extraction, as this environment friendly technique has completely eliminated the use of organic solvents. After describing the effectiveness of microwave radiations in extraction field in the first part of this manuscript, we have optimized this noval extraction method to get antioxidants rich extract. Along with studying the temperature distributions in different parts of plant material under the effect of microwave irradiations, we have analyzed the influence of microwaves in enhancing the antioxidant activity of extracts by using different tests. We have got the promising results concerning about the antioxidant rich extracts of different onion varieties and sea buckthorn in generalization step against the conventional solvent extracts. The application of vacuum system in this extraction system helped in restraining the limitations like dry extract yield and flavonol contents. Incomparison to traditional and recent extraction systems, the MHG extracts doesn’t require any filtration and purification steps as it works in absence of any solvent and water and are highly recommended for direct application in industrial productsL'hydrodiffusion générée par micro-ondes est une nouvelle technique d'extraction mise au point au sein de l'Université d'Avignon et des Pays de Vaucluse. Ce procédé est une combinaison entre une technique traditionnelle et une technologie innovante. En effet, le chauffage par micro-ondes a permis d'initier et de générer le transfert de matière et de chaleur de l"intérieur des matrices végétales (oignons) vers l'extérieur et de réduire de façon considérable les temps d'extraction des antioxydants sans aucune intervention de solvant. A titre de comparaison, les polyphénols de différentes variétés d'oignons ont été extraits par l'hydrodiffusion générée par micro-ondes et par la technique conventionnelle, l'extraction par solvant. Les rendements obtenus par micro-ondes sont presque identiques à ceux obtenus à l'aide d’un solvant alors que les temps d'extraction sont réduits. La capacité antioxydante des extraits micro-ondes est supérieure à celle obtenue par technique conventionelle. Ce qui présage des potentialités d'application dans le domaine agroalimentaire en particulier pour la valorisation des co-produits. Une étude cinétique de l'extraction, ainsi qu'une observation au microscope optique(cytologie) des matrices traitées soumises aux micro-ondes et au solvant ont mis en évidence la spécificité de l'extraction sans solvant assistée par micro-ondes au niveau des mécanismes de libération et d'extraction des molécules antioxydantes au sein du végétal. L'effet des micro-ondes a pour conséquence une libération plus rapide des principes actifs contenue dans la plante grâce à l'ouverture quasi instantanée des glandes et l'explosion des cellules. L'explication de la différence de composition chimique entre les procédés d'extraction par solvant et par micro-ondes pourrait être basée principalement sur des phénomènes de solubilité, de polarisation diélectrique ainsi qu'un transfert de matière et de chaleur inversé
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Hamann, Christine. "Magnetische Hybridschichten - Magnetische Eigenschaften lokal austauschgekoppelter NiFe/IrMn-Schichten." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-64664.
Повний текст джерелаАнотація:
Durch die laterale Modifizierung der magnetischen Eigenschaften von austauschgekoppelten NiFe/IrMn-Schichten wurden weichmagnetische Schichten geschaffen, die sowohl neue statische als auch dynamische hybride Eigenschaften zeigen. Als laterale Strukturierungsmethoden wurden hierbei die lokale Oxidation sowie Ionenimplantation verwendet. Mit Hilfe dieser Verfahren ist es gelungen spezifische magnetische Domänenkonfigurationen mit Streifenstrukturen nominell antiparalleler Magnetisierungsausrichtung in die Schichten einzuprägen. In Abhängigkeit der Strukturorientierung sowie Streifenperiode konnte direkt das Ummagnetisierungsverhalten sowie die magnetische Resonanzfrequenz und Dämpfung der Schichten modifiziert werden. Die neuen dynamischen Eigenschaften wie z.B. eine hybride Resonanzfrequenz werden hierbei im Rahmen der Kopplung über dynamische Ladungen und die direkte Beeinflussung des effektiven Feldes des künstlich eingebrachten Domänenzustandes diskutiert. Die vorgestellten Ergebnisse belegen somit das große Potential der lateralen Magneto-Strukturierung zur Einstellung spezifischer statischer wie auch dynamischer Eigenschaften magnetisch dünner Schichten.
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Castanet, Uli. "Contribution à l’étude des systèmes nanostructurés CeO2, Au et Au/CeO2." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0600/document.
Повний текст джерелаАнотація:
Les nanomatériaux sont de plus en plus utilisés dans de nombreusesapplications, que cela soit pour la catalyse, la coloration, l’optique, etc. Pour optimiser leurutilisation, il est nécessaire de mieux comprendre les réactions et interactions ayant lieu à ceséchelles. Cette thèse se propose d’essayer d’explorer les liens entre conditions de synthèse,morphologie de particules, et propriétés de celles-ci. En particulier, nous avons opté pourl’étude d’un matériau modèle : l’oxyde de cérium (IV). Les nanoparticules de CeO2 ont étéobtenues par voie de synthèse solvothermale assistée par chauffage micro-ondes. Lesmorphologies des nanoparticules de CeO2 étudiées ont été : les cubes, les octaèdres et lesbâtonnets, et nous avons essayé de fournir une explication à leur obtention par la voie desynthèse utilisée. De l’or a ensuite été déposé en surface des ces nanoparticules de CeO2 etétudié par une combinaison d’études par Microscopie Électronique en Transmission et demodélisations numériquesNanomaterials are more and more used in various situations, such as catalysis,color, optics, etc. To optimize their use, it is necessary to better understand reactions andinteractions taking place at these scales. This PhD thesis aims at exploring the links betweensynthesis conditions, particle morphology and their properties. In particular, we chose a tostudy a model-material: cerium (IV) oxide. CeO2 nanoparticles have been obtained bymicrowave-heating assisted solvothermal synthesis. Morphologies obtained and studied havebeen: cubes, octahedrons and rods. We tried to to give an explanation on how these synthesesallowed the formation of such morphologies. Gold has then be deposed on the surface of theseCeO2 nanoparticles, and studied by a combination of Transmission Electron Microscopystudies, and computer modelizations
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Feral-Martin, Cédric. "Influence de la morphologie d’oxydes à base de cérium sur les relations (micro)structures/propriétés." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14076/document.
Повний текст джерелаАнотація:
Les oxydes à base de Cérium, ont fait l’objet de nombreuses études ces dernières décennies et se sont révélés des matériaux de choix, dans le domaine de la catalyse hétérogène. L’objectif à l’heure actuelle, est donc d’accroître la réactivité de ces oxydes, tout en élargissant leur gamme de températures optimales d’utilisation. Dans ce contexte particulier, il semble possible de moduler les propriétés des oxydes à base de cérium en contrôlant la morphologie des cristallites. Ce travail de thèse a donc été consacré à la détermination, l’élaboration et à la caractérisation de matériaux oxydes à base de cérium de morphologies contrôlées. Nous avons tout d’abord déterminé cristallographiquement et thermodynamiquement les morphologies accessibles au système étudié puis par traitement hydrothermale assistée par chauffage micro-ondes nous avons synthétisé les dites morphologies. Après caractérisation de la réactivité par ATG et thermographie Infrarouge nous avons optimisé ces matériaux par un dopage extrinsèque tout d’abord (dépôt de métaux précieux), puis par un dopage intrinsèque ensuite (Yttrium et Fer). Enfin, l’obtention de morphologies non accessibles cristallographiquement nous a amené à approfondir le(s) processus de germination croissance de ces particules et la forte réactivité des matériaux dopés fer nous a poussé à une caractérisation fine de la microstructure de ces matériaux. Au final nous avons pu corréler l’influence de la morphologie des cristallites sur la réactivité propre de l’ensemble des familles de matériaux étudiésRecent decades, numerous studies on cerium-based oxides have been realized and have revealed that cerium-based oxides were materials of choice in the field of heterogeneous catalysis. The aim now is therefore to increase the reactivity of these oxides, while expanding their range of optimal temperatures of Use. In this particular context, it seems possible to modulate the properties of cerium-based oxides by controlling the morphology of the crystallites. This thesis has been devoted to the identification, development and characterization of materials based on cerium oxides of controlled morphology. We first determined possible morphologies for the studied system, by hydrothermal synthesis by micro-wave assisted heating we have synthesized these morphologies and we characterized reactivity of these materials by infrared thermography and TGA. We have optimized these materials first, by extrinsic doping (deposition of precious metals) and then by intrinsic doping (Yttrium and Iron). New morphologies have been synthesized so we have studied the processes of nucleation-growth set in. The high reactivity of iron-doped materials has led us to a detailed characterization of the microstructure of these materials. Finally correlation reactivity/morphologies of crystallites have been achieved
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Бондаренко, И. Н., and А. В. Галич. "Microstrip resonant sensors for scanning microwave microscopy." Thesis, 2014. http://openarchive.nure.ua/handle/document/6774.
Повний текст джерелаАнотація:
The researches of properties of resonant transducers based on segments of microstrip lines, topology of which contains the probe tip structure are carried out. Numerical model studies of the distribution of the fields and the dependence of amplitude-frequency responses of resonant microstrip structures with probes of various configurations are carried out and value of communication and parameters of samples possible diagnosis are determined.
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Mittal, Manoj. "Internal node microwave monolithic integrated circuit diagnostics using scanning electrostatic force microscopy." 1995. http://hdl.handle.net/1993/18947.
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Zhang, Qinxin. "Near-field scanning microwave microscopy and its applications in characterization of dielectric materials." 2006. http://etd.nd.edu/ETD-db/theses/available/etd-06272006-163137/.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Notre Dame, 2006.Thesis directed by Paul J. McGinn for the Department of Chemical and Biomolecular Engineering. "June 2006." Includes bibliographical references (leaves 126-138).
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Гордиенко, Ю. Е., И. Н. Бондаренко, and Н. И. Слипченко. "Biological objects parameters meter based on microwave microscope with coaxial resonant sensor." Thesis, 2010. http://openarchive.nure.ua/handle/document/6764.
Повний текст джерелаАнотація:
The possibilities to use methods and tools of the nearfield microwave microscopy for studying small-dimension
biological objects are analyzed. Methods for optimization of the resonant sensor structure with regard to the objects features are developed, the system of the information signals formation is proposed.
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Chuang, Yung-Han, and 莊詠涵. "A Study of scanning capacitance microscopy on dopant activation and deactivation induced by microwave annealing." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/87570000633380859024.
Повний текст джерелаАнотація:
碩士國立中興大學
物理學系所
105
Scanning capacitance microscopy (SCM) is an important technique measuring two-dimensional carrier distribution in semiconductors. SCM is very suitable for characterizing semiconducting materials because SCM is able to analyze a local area on sample surfaces and highly sensitive to capacitance changes. For instance, one can employed SCM to measure electrical junction depths (EJD), depletion widths, and the effective channel lengths. Microwave annealing (MWA) is an annealing method with a low thermal budget, effectively suppressing dopant diffusion and activating dopant. In this thesis, I used dark-mode SCM to investigate the influence of MWA time on carrier concentration distribution. With MWA time increasing, experimental results indicated that boron and phosphorus in shallow implanted regions have different electrical activation and deactivation behavior. For boron, deactivation occurred prior to activation when the MWA time is longer than 200 seconds. While for phosphorus, significant activation and deactivation were not observed for MWA time longer than 100 seconds. Prior studies indicated that low energy annealing is hard to eliminate the residual lattice defects induced by boron implantation, leading to instability of the boron-active region. However, the energy of MWA is much lower than that of typical thermal annealing. Therefore, the residual lattice defects might affect electrically active boron atoms. In this study, I performed post-annealing MWA to treat boron-implanted n-type silicon substrates and observed instability of the PN junctions formed by MWA. In addition, the influence of MWA sequence on phosphorus activation was also investigated since phosphorus is easy to activate in a short MWA time and exhibits good electrical stability. Experimental results indicated that the post-annealing MWA increased the EJD and the EJD was also closely related to the prior annealing processes.
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Yi-Chun, Chen. "Study on Dielectric Mechanisms of Microwave Materials by Using Full-Band Spectroscopy and Scanning Probe Microscopy." 2002. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0021-1904200713040158.
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Chen, Yi-Chun, and 陳宜君. "Study on Dielectric Mechanisms of Microwave Materials by Using Full-Band Spectroscopy and Scanning Probe Microscopy." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/89767964167508785610.
Повний текст джерелаАнотація:
博士國立臺灣師範大學
物理研究所
91
In this study, full-band dielectric spectroscopy and microwave evanescent microscopy were used to study the intrinsic and extrinsic dielectric mechanism of microwave dielectric materials. Bi1.5Zn1.0Nb1.5O7 and Ba(Mg1/3Ta2/3)O3 ceramics are investigated to reveal the mechanisms for high dielectric constant and high quality factor, respectively. The studied spectrum regimes include: low-frequency band (1 kHz－3 MHz), microwave frequencies (~GHz), submillimeter wave (THz) band, infrared frequency band, and optical (visible light) band. The dominant polarization mechanisms in each band are studied, and the correlation between these mechanisms is discussed. Displasive disorders are found in both the A and O’-sites of Bi1.5Zn1.0Nb1.5O7 pyrochlore structure, A2B2O6O’1, which have significant influences on the dielectric properties of the materials at microwave (~GHz) and lower frequency (1 kHz－3 MHz) bands. The highly polarizable A-site ions, Bi3+, and the asymmetries at A- and O’-sites cause prominant dielectric contributions from A-O and A-O’ related modes, resulting in high dielectric constants at microwave frequencies. Large damping coefficients of these modes also lead to high dielectric losses. In contrast, the displacement disorders mechanism is not operating for high-Q Ba(Mg1/3Ta2/3)O3 ceramics and the dominant dielectric mechanism for theses materials is the polarization of rigid B”O6 octahedra in the complex perovskite structure A(B’1/3B”2/3)O3. Microwave dielectric constants are influenced by the rigidity of the three-dimensional oxygen-octahedron network, while the microwave quality factors, Q×f values, are related to the distortion of B”O6 oxygen octahedron. In the study of extrinsic mechanism, EMP images reveal that samples with inferior dielectric properties usually contain large proportion of low-K and low-Q secondary phase. Moreover, scanning Raman spectroscopy reveals the presence of grains with distorted crystal structure. These defects degrade the macroscopic dielectric properties, and are the main extrinsic mechanisms modifying ceramic properties.
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Lai, Kwei-Yuan, and 賴奎元. "Development of Near-field Scanning Microwave Microscope (NSMM)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/85634184049494213969.
Повний текст джерелаАнотація:
碩士國立臺灣師範大學
物理學系
104
In order to achieve surface impedance topography and submicron level magnetic domain image as well as extend our greatest interest and expertise of spin dynamic measurement, so called ferromagnetic resonance (FMR), to local ferromagnetic resonance measurement(LFMR), we are dedicated to developing a near-field scanning microwave microscope (NSMM). Self-configured scanning tunneling microscope (STM) and NSMM employing RHK R9 SPM controller, n.point C.300 piezoelectric stage and Agilent N5230C network analyzer are demonstrated in this dissertation. Developmental processes can be mainly divided into STM part and NSMM part. In STM part, designs of main body, vibration isolation, automatic approach system, and tip fabrication are demonstrated. In NSMM part, two different configurations adopting microwave components, vector network analyzer (VNA), and NI my DAQ, are discussed. Finishing constructing, various samples were employed to test performance of the instruments. Cu-coated 4.7 GB DVD fabricated by pulse laser deposition (PLD) was used as STM test sample. For NSMM’s test samples, Au/Si alternatively stripped samples with three different dimensions, 25 um/ 25 um, 10 um/ 10 um, and 2 um/ 18 um, were fabricated by electron beam lithography (EBL) and vacuum thermal evaporation deposition (VTED). An AFM standard silicon test sample with dimensions of 5 um in x, y and 180 nm in z was also scanned to discriminate the influence of 100-nm thickness of Au strips from surface impedance. Hundred-nanometer spatial resolution has been achieved by our STM with set-point current 0.8 nA and bias voltage 1.5 V. A set of chemically-etching equipment are also developed and are capable of producing sharp tips with apex diameter less than 100 nm under parameters of 4 V KOH, 8 V etching voltage, and 2 V cut-off voltage. This apex is very ideal for scanning probe microscope (SPM) uses. Most critically, the self-developed NSMM configuration using VNA, PC and NI my DAQ. This novel yet simple configuration enables our NSMM to miraculously accomplishλ/10000-wavelength-relative resolution as well as sensitivity less than 0.01 dB while working over 13 GHz.
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MATĚJÍČEK, Jan. "Plazmová modifikace materiálů pro medicinální účely." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-202657.
Повний текст джерелаАнотація:
This diploma thesis deals with the ongoing research under the auspices of the Department of Applied Physics and Technics Faculty of Education, University of South Bohemia in České Budějovice, in which the author of the work was actively participated. The thesis is divided into theoretical and experimental part. The theoretical part contains information from natural polymers, especially cellulose, plasma technology and infrared spectrometry. The subject of the experimental part of the thesis is research that deals with the functionalization of cellulose using a microwave plasma discharge on the apparatus CX-22. In the present research was also conducted to process optimization of functionalization with the liquid precursor hexamethyldisiloxane (HMDSO).
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張, 嵐., and Lan ZHANG. "A Study on the Development of Microwave Atomic Force Microscope." Thesis, 2012. http://hdl.handle.net/2237/16493.
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Berta, Milan. "Vývoj a využití zobrazovacích metod v blízkém poli v terahertzové spektrální oblasti." Doctoral thesis, 2011. http://www.nusl.cz/ntk/nusl-299147.
Повний текст джерелаАнотація:
We are reporting on a study of the near-field sensitivity and resolution of a metal-dielectric probe (MDP). The propagation of the electromagnetic field across the probe was studied experimentally by means of time-domain terahertz spectroscopy and numerically simulated by CST MicroWave Studio 2008. Several localised areas at the probe end facet were distinguished and showed to be sensitive to the local dielectric properties and local anisotropy of the sample. Contrast and sensitivity measurements were conducted in several configurations of a MDP; the results were confirmed by simulations. The acquired data were analysed by using singular value decomposition that enabled separating independent physical phenomena in the measured datasets and filtering external disturbances out of the signal. Independent components corresponding to the changes in the output terahertz pulse upon varying the probe-sample distance and reflecting the local anisotropy in a ferroelectric barium titanate (BaTiO3) crystal were extracted and identified. The domain structure with characteristic dimensions of about 5 um was resolved during imaging experiments on the ferroelectric BaTiO3 sample, i.e. the resolved structures were ten times smaller than the characteristic dimensions of the end facet of the probe and forty times smaller than...