Literatura académica sobre el tema "Carbone nanotubes microwave device"
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Artículos de revistas sobre el tema "Carbone nanotubes microwave device"
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Tripon-Canseliet, Charlotte, Stephane Xavier, Yifeng Fu, Jean-Paul Martinaud, Afshin Ziaei y Jean Chazelas. "Experimental Microwave Complex Conductivity Extraction of Vertically Aligned MWCNT Bundles for Microwave Subwavelength Antenna Design". Micromachines 10, n.º 9 (27 de agosto de 2019): 566. http://dx.doi.org/10.3390/mi10090566.
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This paper reports the extraction of electrical impedance at microwave frequencies of vertically aligned multi-wall carbon nanotubes (VA MWCNT) bundles/forests grown on a silicon substrate. Dedicated resonating devices were designed for antenna application, operating around 10 GHz and benefiting from natural inductive/capacitive behavior or complex conductivity in the microwave domain. As obtained from S-parameters measurements, the capacitive and inductive behaviors of VA MWCNT bundles were deduced from device frequency resonance shift.
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Liu, Jih-Hsin y Yao-Sheng Huang. "Development of Microwave Filters with Tunable Frequency and Flexibility Using Carbon Nanotube Paper". Nanomaterials 13, n.º 18 (5 de septiembre de 2023): 2497. http://dx.doi.org/10.3390/nano13182497.
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This study aims to exploit the distinctive properties of carbon nanotube materials, which are particularly pronounced at the microscopic scale, by deploying fabrication techniques that allow their features to be observed macroscopically. Specifically, we aim to create a semiconductor device that exhibits flexibility and the ability to modulate its electromagnetic wave absorption frequency by means of biasing. Initially, we fabricate a sheet of carbon nanotubes through a vacuum filtration process. Subsequently, phosphorus and boron elements are separately doped into the nanotube sheet, enabling it to embody the characteristics of a PN diode. Measurements indicate that, in addition to the fundamental diode’s current–voltage relationship, the device also demonstrates intriguing transmission properties under the TEM mode of electromagnetic waves. It exhibits a frequency shift of approximately 2.3125 GHz for each volt of bias change. The final result is a lightweight and flexible carbon-based semiconductor microwave filter, which can conform to curved surfaces. This feat underscores the potential of such materials for innovative and effective electromagnetic wave manipulation.
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BURKE, P. J., C. RUTHERGLEN y Z. YU. "SINGLE-WALLED CARBON NANOTUBES: APPLICATIONS IN HIGH FREQUENCY ELECTRONICS". International Journal of High Speed Electronics and Systems 16, n.º 04 (diciembre de 2006): 977–99. http://dx.doi.org/10.1142/s0129156406004119.
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In this paper, we review the potential applications of single-walled carbon nanotubes in three areas: passives (interconnects), actives (transistors), and antennas. In the area of actives, potential applications include transistors for RF and microwave amplifiers, mixers, detectors, and filters. We review the experimental state of the art, and present the theoretical predictions (where available) for ultimate device performance. In addition, we discuss fundamental parameters such as dc resistance as a function of length for individual, single-walled carbon nanotubes.
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Koshikawa, Yusuke, Ryo Miyashita, Takuya Yonehara, Kyoka Komaba, Reiji Kumai y Hiromasa Goto. "Conducting Polymer Metallic Emerald: Magnetic Measurements of Nanocarbons/Polyaniline and Preparation of Plastic Composites". C 8, n.º 4 (4 de noviembre de 2022): 60. http://dx.doi.org/10.3390/c8040060.
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Synthesis of polyaniline in the presence of fullerene nanotubes (nanocarbons) in water was carried out with oxidative polymerization. The surface of the sample showed metallic emerald green color in bulk like the brilliance of encrusted gemstones. The composite showed unique magnetic behavior, such as microwave power-dependent magnetic resonance as magnetic spin behavior and macroscopic paramagnetism with a maximum χ value at room temperature evaluated with superconductor interference device. Surface structure of the composite was observed with optical microscopy, circular polarized differential interference contrast optical microscopy, scanning electron microscopy, and electron probe micro analyzer. Polymer blends consisting of polyaniline, nano-carbons, and hydroxypropylcellulose or acryl resin with both conducting polymer and carbon characters were prepared, which can be applied for electrical conducting plastics. The combination of conducting polymer and nano-carbon materials can produce new electro-magneto-active soft materials by forming a composite. This paper reports evaluation of magnetic properties as a new point of nanocarbon and conducting polymer composite.
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Chen, Ying-Chu, Yu-Kuei Hsu, Yan-Gu Lin, Li-Chyong Chen y Kuei-Hsien Chen. "Spontaneous Synthesis and Electrochemical Characterization of NanostructuredMnO2on Nitrogen-Incorporated Carbon Nanotubes". International Journal of Electrochemistry 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/475417.
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This paper investigated the layered manganese dioxide with hydrate (MnO2⋅xH2O) deposits onto nitrogen-containing carbon nanotube (CNxNTs) as a hierarchical electrode for an energy-storage device. The dense and entangled CNxNTs were directly grown by microwave plasma-enhanced chemical vapor deposition (MPECVD) on a carbon cloth (CC), and subsequently used as a current collector. By controlling the pH value of KMnO4precursor solution, and incorporating nitrogen into CNTs as a reducing agent, the MnO2thin layer was uniformly fabricated on the CNxNTs at room temperature by using a spontaneous reduction method. The role of incorporation nitrogen is not only capable of creating active sites on the CNT surface, but can also donate electrons to reduceMnO4-to MnO2spontaneously. From the measurements of cyclic voltammograms and galvanostatic charge/discharge, MnO2/CNxNTs/CC composite electrodes illustrated excellent specific capacitance of 589.1 Fg-1. The key factor for high performance could be attributed to the thin-layered MnO2nanostructure, which resulted in the full utilization of MnO2deposits. Hence, the hierarchically porous MnO2/CNxNTs/CC electrodes exhibited excellent capacitive behavior for electrochemical capacitor application.
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Motshekga, Sarah C., Sreejarani K. Pillai, Suprakas Sinha Ray, Kalala Jalama y Rui W. M. Krause. "Recent Trends in the Microwave-Assisted Synthesis of Metal Oxide Nanoparticles Supported on Carbon Nanotubes and Their Applications". Journal of Nanomaterials 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/691503.
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The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other nanostructures to their surface. The combination of the distinctive properties of carbon nanotubes and metal/oxides is expected to be applied in field emission displays, nanoelectronic devices, novel catalysts, and polymer or ceramic reinforcement. The synthesis of these composites is still largely based on conventional techniques, such as wet impregnation followed by chemical reduction of the metal nanoparticle precursors. These techniques based on thermal heating can be time consuming and often lack control of particle size and morphology. Hence, there is interest in microwave technology recently, where using microwaves represents an alternative way of power input into chemical reactions through dielectric heating. This paper covers the synthesis and applications of carbon-nanotube-coated metal/oxides nanoparticles prepared by a microwave-assisted method. The reviewed studies show that the microwave-assisted synthesis of the composites allows processes to be completed within a shorter reaction time with uniform and well-dispersed nanoparticle formation.
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Mathur, A., S. S. Roy y J. A. McLaughlin. "Transferring vertically aligned carbon nanotubes onto a polymeric substrate using a hot embossing technique for microfluidic applications". Journal of The Royal Society Interface 7, n.º 48 (10 de febrero de 2010): 1129–33. http://dx.doi.org/10.1098/rsif.2009.0520.
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We explored the hot embossing method for transferring vertically aligned carbon nanotubes (CNTs) into microfluidic channels, fabricated on poly-methyl-methacrylate (PMMA). Patterned and unpatterned CNTs were synthesized by microwave plasma-enhanced chemical vapour deposition on silicon to work as a stamp. For hot embossing, 115°C and 1 kN force for 2 min were found to be the most suitable parameters for the complete transfer of aligned CNTs on the PMMA microchannel. Raman and SEM studies were used to analyse the microstructure of CNTs before and after hot embossing. The PMMA microparticles with dimensions (approx. 10 µm in diameter) similar to red blood cells were successfully filtered using laminar flow through these microfluidic channels. Finally, a microfluidic-based point-of-care device for blood filtration and detection of bio-molecules is drawn schematically.
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Mani, Veerappan, T. S. T. Balamurugan y Sheng-Tung Huang. "Rapid One-Pot Synthesis of Polydopamine Encapsulated Carbon Anchored with Au Nanoparticles: Versatile Electrocatalysts for Chloramphenicol and Folic Acid Sensors". International Journal of Molecular Sciences 21, n.º 8 (19 de abril de 2020): 2853. http://dx.doi.org/10.3390/ijms21082853.
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Designing and engineering nanocomposites with tailored physiochemical properties through teaming distinct components is a straightforward strategy to yield multifunctional materials. Here, we describe a rapid, economical, and green one-pot microwave synthetic procedure for the preparation of ternary nanocomposites carbon/polydopamine/Au nanoparticles (C/PDA/AuNPs; C = carbon nanotubes (CNTs), reduced graphene oxide (rGO)). No harsh reaction conditions were used in the method, as are used in conventional hydrothermal or high-temperature methods. The PDA unit acts as a non-covalent functionalizing agent for carbon, through π stacking interactions, and also as a stabilizing agent for the formation of AuNPs. The CNTs/PDA/AuNPs modified electrode exhibited excellent electrocatalytic activity to oxidize chloramphenicol and the resulting sensor exhibited a low detection limit (36 nM), wide linear range (0.1–534 μM), good selectivity (against 5-fold excess levels of interferences), appreciable reproducibility (3.47%), good stability (94.7%), and practicality (recoveries 95.0%–98.4%). Likewise, rGO/PDA/AuNPs was used to fabricate a sensitive folic acid sensor, which exhibits excellent analytical parameters, including wide linear range (0.1–905 μM) and low detection limit (25 nM). The described synthetic route includes fast reaction time (5 min) and a readily available household microwave heating device, which has the potential to significantly contribute to the current state of the field.
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Maratta Martínez, Ariel, Sandra Vázquez, Rodolfo Lara, Luis Dante Martínez y Pablo Pacheco. "Selenium analysis by an integrated microwave digestion-needle trap device with hydride sorption on carbon nanotubes and electrothermal atomic absorption spectrometry determination". Spectrochimica Acta Part B: Atomic Spectroscopy 140 (febrero de 2018): 22–28. http://dx.doi.org/10.1016/j.sab.2017.12.001.
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Mathur, A., Tuhin Maity, Shikha Wadhwa, B. Ghosh, Sweety Sarma, Sekhar C. Ray, Bhaskar Kaviraj, Susanta S. Roy y Saibal Roy. "Magnetic properties of microwave-plasma (thermal) chemical vapour deposited Co-filled (Fe-filled) multiwall carbon nanotubes: comparative study for magnetic device applications". Materials Research Express 5, n.º 7 (4 de julio de 2018): 076101. http://dx.doi.org/10.1088/2053-1591/aacddb.
Texto completoTesis sobre el tema "Carbone nanotubes microwave device"
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Beccacece, Lorenzo. "Electromagnetic interaction between multi-walled carbon nanotube bundles". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS268.
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L’utilisation des matériaux 1D et 2D dans les dispositifs électroniques suscite un intérêt dans la communauté scientifique et industriel. Grâce à leurs propriétés uniques, les chercheurs envisagent la miniaturisation de dispositifs électroniques fabriqués. Les nanotubes de carbone font partie des matériaux 1D. Après avoir fait l’état de l’art concernant le matériau et son intégration dans les dispositifs électroniques, on a pu déterminer de nouveaux axes de recherche. Ce travail de thèse porte sur la synthèse, caractérisation, modélisation et intégration des fagots verticaux de nanotubes de carbone multi-parois (VAMWCNTs), dans des dispositifs hyperfréquences. L’objectif a été d’améliorer la compréhension du comportement électrique du matériau dans le domaine hyperfréquence, et d’étudier l’interaction électromagnétique entre deux fagots de VAMWCNTs. Ces objectifs font que ce travail de thèse propose une étude novatrice. Des caractérisations avancées ont été réalisées sur ce matériau, et ceci afin de déterminer leurs caractéristiques. Deux modèles électriques équivalents ont été proposés et implémentés par des simulations numériques afin de calculer leurs impédance électrique complexe. Ces résultats de caractérisation ont été utilisés a posteriori pour valider, et aussi pour améliorer ces modèles. Un procédé de fabrication en salle blanche a été optimisé dans le but de synthétiser les fagots de VAMWCNTs directement sur les pistes métalliques.Un dispositif hyperfréquence a été conçu pour étudier le couplage électromagnétique entre deux fagots verticaux de VAMWCNTs. Les mesures montrent l’existence d’un effet qui peut être attribué aux couplages capacitif et magnétiqueThe use of 1D and 2D materials in electronic devices is a matter of interest for the scientific and industrial communities. Thanks to their unique properties, the researchers want to reach the device miniaturization. The carbon nanotubes are part of the 1D materials. After the study of the state of the art on this material and on its integration in electronic devices, we defined new research issues on the matter. The work performed in this Ph.D. covered the synthesis, characterization, modeling and integration of vertically aligned multi-walled carbon nanotube (VAMWCNT) bundles, in microwave devices. The goal was to have a better comprehension of the electrical behavior of the synthetized material in the microwave spectrum, and to test the electromagnetic interaction between two large VAMWCNT bundles. This subject has never been previously explored. Advanced characterizations have been achieved on the material, to determine their quality and properties. Two equivalent electrical models, implemented with numerical experiments, were proposed to have the frequency-dependent behavior of the complex electrical impedance. The characterization results were used as feedback to validate and also to improve the models. A clean room fabrication process was optimized, in order to synthetize the VAMWCNT bundles directly on the metallic lines of the devices, and to study the impact of the synthesis. Finally, a microwave device was designed to study the electromagnetic coupling between two large VAMWCNT bundles. The measurements permitted to observe an effect which can be attributed to their capacitive and magnetic coupling
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BARBOSA, GELZA DE MOURA. "MICROWAVE DEVICES USING CARBON NANOTUBES AND GRAPHENE". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23541@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROEsta Tese consiste na pesquisa, dimensionamento e desenvolvimento de estruturas de microondas que utilizam grafeno e nanotubos de carbono como componente fundamental. São apresentadas aplicações em dispositivos de micro-ondas e no domínio óptico, tais como filtros, conversores de frequência, antenas de microondas, absorvedores de microondas etc. Também são apresentados os resultados dos testes realizados em todos os dispositivos desenvolvidos. Alguns dispositivos contém inovações ainda não reportadas na literatura.
This Thesis consists inthe research, dimensioning and design of microwave structures that use graphene and carbon nanotubes as fundamental component. Applications are presented in microwave devices and in the optical domain, such as filters, frequency converters, microwave antennas, microwave absorber etc. Besides that, the results of the tests performed in all designed devices are presented. Some devices have innovations not yet reported in the literature.
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Gasper, Michael Robert. "Characterizations and Applications of Carbon Nanotube Thin Film Devices". University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1470304282.
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Abdelghani, Aymen. "Capteur de gaz hyperfréquence à base de nanotubes de carbone, imprimé par technologie jet d’encre". Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0089/document.
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Au cours de ces dernières années, le développement des capteurs de gaz a connu un essor grandissant pour des applications industrielles, militaires et environnementales afin d’assurer la sécurité et la protection contre les gaz nocifs et toxiques. Ces applications demandent des capteurs sensibles, sélectifs, à faible consommation d’énergie et à faible coût. Le travail de thèse présenté dans ce manuscrit, s’inscrit dans ce contexte. Il a pour objectif la réalisation d’un capteur hyperfréquence à base de nanotubes de carbone et fabriqué par technologie jet d’encre. Le principe de fonctionnement du capteur repose sur la caractérisation en fréquence d’un résonateur RF, dont un élément est sensible grâce aux nanotubes de carbone, à la présence d’un gaz environnant. Le manuscrit aborde l’ensemble des étapes nécessaires à la réalisation du capteur, à savoir : la conception des dispositifs de test, s’appuyant sur une étude théorique de leur comportement, la caractérisation des matériaux utilisées, la fabrication sur un substrat flexible par une technique d’impression jet d’encre et enfin la caractérisation du capteur de gaz en termes de comportement en fréquence et de sensibilité en présence de gazIn recent years, the development of gas sensors has grown rapidly for industrial, military and environmental applications to ensure safety and protection against harmful and toxic gases. These applications require sensitive, selective, low power and low cost sensors. The thesis work presented in this manuscript fits into this context. Its objective is the realization of a microwave sensor based on carbon nanotubes and manufactured by inkjet technology. The operating principle of the sensor is based on the frequency characterization of an RF resonator, one element of which is sensitive, thanks to the carbon nanotubes, to the presence of a surrounding gas. The manuscript addresses all the steps necessary for the realization of the sensor, namely: the design of the test devices, based on a theoretical study of their behavior, the characterization of the materials used, the fabrication on a flexible substrate by inkjet printing technique and finally the characterization of the gas sensor in terms of frequency behavior and sensitivity in the presence of gas
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Lei, Ya-Jie. "Élaboration de matériaux hautement stable thermiquement par modification et fonctionnalisation de la résine bisphthalonitrile". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0265.
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Les polymères de phtalonitrile sont obtenus par des réactions d'addition des groupements cyano à haute température et pour un temps long à partir de dérivés de phtalonitrile. Ils trouvent de nombreuses applications dans les domaines de pointe comme l'aérospatiale et la marine. Cependant, leurs performances sont limitées par les inconvénients suivants : (1) fragilité liée intrinsèquement à leur réseau structural, (2) température de fusion élevée, fenêtre de conditions de mise en forme étroite, température de cuisson élevée, cinétique de cuisson faible, (3) Selon la litérature, le traitement du bisphthalonitrile pour obtenir la résine correspondante s'effectue souvent à des températures inférieures à 500°C. Il y a peu d'études sur les matériaux formés à des températures supérieures à celle-ci, (4) Il n'y a pas beaucoup d'études sur la fonctionnalisation de la résine bisphthalonitrile et son domaine d'application doit être élargis. Cette thèse porte sur le dévelopement de méthodes permettant la modification et la fonctionnalisation de la résine bisphthalonitrile conduisant à une amelioration des propriétés mécaniques de celle-ci. De plus, des nanotubes de carbone ayant une morphologie différente et des matériaux capables d'absorber les hyperfréquences ont été obtenus par pyrolyse de la résine bisphthalonitrile en présence de différents catalyseurs de fer et sur une plage de température allant de 600 a 900°CBisphthalonitrile polymers are obtained by addition curing reaction of cyano groups upon heating phthalonitrile derivatives at elevated temperature and for an extended period of time. They have found many applications in advanced technologies such as aerospace and marine. However, their performances are limited by the following disadvantages: (1) high brittleness of the inherent network structure; (2) high melting temperature, narrow processing window, high curing temperature, low curing rate and long curing time; (3) according to the literature, the processing temperature of bisphthalonitrile resin-based composites is controlled at 500°C or less, whereas there are few studies on materials formed above 500°C; (4) studies on the functionalization of bisphthalonitrile resins are not abundant and its application range needs to be expanded. Based on the above statement, this thesis is focused on the modification and functionalization of bisphthalonitrile resins. The latter were modified by a variety of methods, resulting in improved mechanical properties. Moreover, carbon nanotubes with different morphologies and microwave absorbing materials were obtained by pyrolysing bisphthalonitrile resins with different metal iron catalysts in the range of 600 to 900°C
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Lang, Volker. "Electrically detected magnetic resonance in semiconductor and carbon nanodevices". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:614ed1d1-0304-4356-8bd3-eb0ce7bd6c9d.
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Electrically detected magnetic resonance (EDMR) is a sensitive spectroscopic technique, which can be used to readout few to single electron spins in semiconductor and carbon nanodevices for applications in solid state quantum information processing (QIP). Since only electrically active defects contribute to the EDMR signal, this technique can be used further to investigate defects and impurities in photovoltaic devices, in which they limit the sunlight-to-energy conversion efficiency significantly. Here, I employ X-band EDMR for semiconductor defect analysis and identify the most important recombination centres in Czochralski silicon with oxide precipitates, which can be intentionally grown to confine detrimental metallic impurities to inactive regions of the wafer in order to serve as a defect-free substrate for modern silicon photovoltaic devices. Those experiments show that oxide precipitation is accompanied by the formation of silicon dangling bonds. Furthermore, I describe a very promising route towards the fabrication and readout of few to single electron spins in carbon nanotube devices, which can be characterised structurally via transmission electron microscopy in order to relate their electrical and spin properties with their structure. Finally, I employ EDMR to read out electron spin states in donor-doped silicon field-effect transistors as a prerequisite for their application in QIP. I report on a novel cryogenic probe head for EDMR experiments in resonant microwave cavities operating at 0.35 T (9.7 GHz, X-band) and 3.34 T (94 GHz, W-band). This approach overcomes the inherent limitations of conventional X-band EDMR and permits the investigation of paramagnetic states with a higher spectroscopic resolution and signal intensity. Both advantages are demonstrated and discussed. I further report on a novel mechanism giving rise to the EDMR effect in donor-doped silicon field-effect transistors, which is capable of explaining why the EDMR signal intensities of the conduction electrons are enhanced by a factor of ∼100, while the donor resonance signals increase by a factor of ∼20 from X- to W-band only. The spin-relaxation and dephasing times are extracted from a series of pulsed-EDMR measurements and confirm this model. The author gratefully acknowledges funding from Trinity College Oxford, Department of Materials, EPSRC DTA, and Konrad-Adenauer-Stiftung e.V. (Begabtenförderung).
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Contamin, Lauriane. "Mise en évidence de textures de spin synthétiques par des mesures de transport et de champ microonde". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEE020.
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Dans cette thèse, nous avons étudié des nanocircuits à base de nanotubes de carbone intégrées dans une cavité micro-onde. Notre dispositif permet de réaliser simultanément des mesures de transport et des mesures micro-ondes, qui donnent des informations complémentaires sur le nanocircuit. Dans les deux expériences réalisées durant cette thèse, un nanotube de carbone est placé au-dessus d’un matériau magnétique qui présente plusieurs domaines d’aimantation. L’axe du champ magnétique de fuite résultant oscille le long du nanotube. Pour les électrons confinés, il est équivalent à un couplage spin-orbite synthétique et à un effet Zeeman. Cet effet synthétique est mis en évidence de deux manières. Dans une première expérience, nous avons mesuré l’évolution des niveaux d’énergie de la boîte quantique quand le matériau magnétique est progressivement aimanté par un champ extérieur, ce qui détruit le champ oscillant. Dans cette expérience, le nanotube a un très bon contact avec un métal supraconducteur en supplément des effets spin-orbite et Zeeman synthétique, qui sont les prérequis pour obtenir des quasiparticules de Majorana dans un nanoconducteur 1D. De telles quasiparticules sont activement recherchées pour leur utilisation pour le calcul quantique. Dans un second temps, nous avons réalisé une double boîte quantique, dans laquelle chaque boîte est constituée d’un segment de nanotube, situé au-dessus du même champ magnétique oscillant que dans la première expérience. Les transitions internes de ce système sont mesurées à l’aide de la cavité micro-onde. Nous avons mis en évidence une très forte dispersion de l’énergie de la transition interne avec un faible champ magnétique extérieur, qui peut être expliqué par un effet Zeeman pour lequel le facteur de Landé, g, a été fortement renormalisé par l’interaction spin-orbite synthétiqueIn this thesis, we have studied carbon nanotube-based nanocircuits integrated in a microwave cavity architecture. Our device is compatible with the simultaneous measurement of both the current through the nanocircuit and the frequency shift of the cavity. These two signals give complementary information about the device. In the two experiments presented in this thesis, the carbon nanotube was positioned above a magnetic material containing several magnetization domains. The resulting magnetic stray field’s axis oscillates along the carbon nanotube length. For the confined electrons, this is equivalent to both a synthetic spin-orbit interaction and a Zeeman effect. This synthetic effect is evidenced in two ways. In a first experiment, we have measured the evolution of the nanotube’s energy levels when the magnetic material is progressively magnetized by an external magnetic field, thus destroying the oscillations of the stray field. In this experiment, the carbon nanotube had a very transparent contact to a superconducting metal, in addition to the synthetic spin-orbit interaction and Zeeman effect. These ingredients are a pre-requisite to observe Majorana quasiparticles in a one-dimensional nanoconductor. Those quasiparticles are under intense study for their potential use in quantum computing. In the second experiment, we have realized a double quantum dot in which each dot similarly lays above an oscillating magnetic field. The internal transitions of this DQD are measured with the microwave cavity signal. We evidenced a strong dispersion of the energy of the double quantum dots’ internal transitions with a small external magnetic field. This dispersion can be explained by a Zeeman effect in which the Landé factor, g, has been strongly renormalized by the synthetic spin-orbit interaction
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Zhang, Anne. "Corrélation entre la structure multi-échelle de composites à charges conductrices et leurs performances en furtivité multi-bande". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASC011.
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Les matériaux absorbants radar ont fait leur apparition à l’époque de la Seconde Guerre Mondiale afin de rendre furtifs les équipements militaires. Depuis, et pour de nombreuses applications non seulement militaires mais également industrielles et civiles, le besoin de matériaux absorbants multifonctionnels ne cesse d’augmenter. Nous proposons dans cette thèse de développer un composite original à renfort tissé et à conductivité réglée pour application en absorption dans le domaine micro-ondes. Les charges conductrices, les nanotubes de carbone (NTC), sont greffées directement sur le tissu de verre (TV) servant de substrat, grâce à un procédé de synthèse continue par dépôt chimique en phase vapeur (CVD). Les structures hybrides NTC-TV en résultant présentent des morphologies particulières qui confèrent des propriétés intéressantes aux composites à matrice époxyde auxquels ils sont intégrés, du fait de leur structure multi-échelle. Les objectifs de cette thèse sont les suivants : optimiser le procédé de synthèse CVD continu en maîtrisant les paramètres expérimentaux pour déposer des NTC sur de grandes longueurs de tissu de façon reproductible, corréler la morphologie multi-échelle particulière des composites hybrides NTC TV/époxy à leurs propriétés diélectriques et leurs capacités d’absorption dans la gamme 1 – 18 GHz, et enfin obtenir des composites performants i.e. absorbants sur de larges bandes de fréquences. La compréhension des mécanismes d’absorption des composites hybrides s’appuie notamment sur l’étude de composites « modèles » NTC/époxy, fabriqués à partir de NTC commerciaux. Les deux types de composites ont permis d’obtenir de bonnes performances en absorption électromagnétiqueRadar absorbing materials appeared around Second World War to make military devices stealthy. Ever since, the demand for multifunctional microwave absorbing materials has continuously grown to meet not only military, but also industrial and civilian applications. In the present work, we propose a novel glass fabric (GF)-reinforced composite with tuned conductivity for microwave absorption applications. The chosen conductive fillers, carbon nanotubes (CNT), are directly grafted onto the glass fibers through a continuous chemical vapor deposition process (CVD). The resulting CNT-GF hybrid structures display intricate morphologies leading to interesting properties of the multi-scale composites fabricated by impregnating them into an epoxy matrix. The goals of this thesis include: understanding and mastering the continuous CVD process in order to grow CNT on considerable lengths of glass fabric, correlating the multiscale morphology of the CNT-GF/epoxy hybrid composites and their dielectric properties and absorption abilities in the 1 – 18 GHz frequency range, and ultimately obtaining composites displaying good absorption performances over large frequency bands. The investigation of the absorption mechanisms of the hybrid composites relies on the study of “model” CNT/epoxy composites fabricated from commercial CNT. Both types of composites resulted in good electromagnetic absorption
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Liao, Si-yu. "Caractérisation électrique et électro-optique de transistor à base de nanotube de carbone en vue de leur modélisation compacte". Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14254/document.
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Afin de permettre de développer un modèle de mémoire non-volatile basée sur le transistor à nanotube de carbone à commande optique qui est utilisée dans des circuits électroniques neuromorphiques, il est nécessaire de comprendre les physiques électroniques et optoélectroniques des nanotubes de carbone, en particulier l’origine de l'effet mémoire que présente ces transistors. C’est dans ce contexte général que cette thèse s'intègre. Le travail est mené sur trois plans :• Caractériser électriquement et optoélectroniquement des structures de test des CNTFETs et des OG-CNTFETs.• Développer un modèle compact pour les contacts Schottky dans les transistors à nanotube de carbone de la façon auto-cohérente basé sur le diamètre et la nature du métal d’électrode en utilisant la méthode de la barrière effective avec les paramètres nécessaires calibrés.• Modéliser l'OG-CNTFET selon les régimes de fonctionnement, lecture, écriture, effacement ou programmation pour application à une mémoire non-volatile en intégrant le mécanisme de piégeage et dépiégeage à l’interface polymère/oxydeThis PhD thesis presents a computationally efficient physics-based compact model for optically-gated carbon nanotube field effect transistors (OG-CNTFETs), especially in the non-volatile memory application. This model includes memory operations such as “read”, “write”, “erase” or “program”, and “reset” which are modeled using trapping and detrapping mechanisms at the polymer/oxide interface. The relaxation of the memory state is taken into account. Furthermore, the self-consistent modeling of Schottky barriers at contacts between the carbon nanotube channel and metal electrodes is integrated in this model applying the effective Schottky barrier method. The Schottky contact model can be included in CNTFET based devices for a typical biasing range of carbon nanotube transistors. This compact model is validated by the good agreement between simulation results and experimental data (I-V characteristics). In the non-volatile memory application, this model can fully reproduce device behaviors in transient simulations. A prediction study of the key technological parameter, the CNT diameter variety is established to expect its impact on the transistor performance, and more importantly, on the memory operation. In the other hand, this thesis presents a preliminary electric characterization (I-V) of CNTFETs and OG-CNTFETs for the device modeling database. A preliminary optoelectronic characterization method is proposed
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Forel, Salomé. "Single wall carbon nanotube growth from bimetallic nanoparticles : a parametric study of the synthesis up to potential application in nano-electronics". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX094/document.
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Ce manuscrit présente une étude expérimentale autour de la synthèse des nanotubes de carbone et de leurs possibles intégrations dans des dispositifs. Les remarquables propriétés électroniques et optiques des nanotubes en font un matériau de choix pour entre autres, la nanoélectronique. Néanmoins, l’intégration des nanotubes dans des dispositifs performants est encore aujourd’hui un défi. Cela repose principalement sur la difficulté d’obtenir de grandes quantités de nanotubes mono-paroi avec des propriétés uniformes, propriétés qui sont définies par la structure du nanotube (i.e. leur angle chiral et leur diamètre). Ainsi, réaliser des synthèses de nanotube de carbone avec un contrôle de leur structure représente un point clé pour le progrès dans ce domaine.Nous avons donc mis en place une nouvelle méthode de synthèse de nanotubes de carbone basée sur la chimie de coordination et le dépôt chimique en phase vapeur activé par filament chaud. Cette synthèse permet la conception de nombreux nouveaux catalyseurs bimétalliques pour la croissance des nanotubes de carbone. Comme le procédé mis en place est très générique, des études paramétriques peuvent être réalisées de manière à mieux comprendre l’influence des différents paramètres de la croissance sur la structure des nanotubes obtenue. Nous discuterons ici du rôle de la température et de la composition chimique du catalyseur. Les nanotubes obtenus sont principalement caractérisés par spectroscopie Raman et par microscopies électroniques.Afin de valider les observations obtenues par spectroscopie Raman, les nanotubes synthétisés ont aussi été intégrés dans des dispositifs de type transistor à effet de champ. Une analyse des performances des transistors en fonction des différents nanotubes utilisés dans le canal est présentée.Enfin, les nanotubes intégrés dans ces transistors ont été fonctionnalisés avec un chromophore de ruthénium. Nous avons montré que cette fonctionnalisation nous permet de moduler, grâce à une impulsion lumineuse, la conductivité du dispositif sur trois ordres de grandeurThis manuscript presents an experimental study around the single wall carbon nanotubes (SWCNT) synthesis and their possible integration in nanodevices. The unique electronic and optical properties of carbon nanotubes make them a choice material for various applications, particularly in nano-electronics.Nevertheless, their integration in effective devices is still a challenge. This is mainly due to the difficulty to obtain large quantity of SWCNT with uniform properties, defined by their structure (i.e. chiral angle and diameter). Therefore, structure controlled growth of SWCNTs is a key point for progress in this field.Here, we established a new synthesis approach based on coordination chemistry and hot-filament chemical vapor deposition. This approach allows the design of various bimetallic catalyst nanoparticles for the SWCNT growth. As the synthesis process is generic, parametric study can be performed in order to better understand the influence of the various parameters on the structure of the as-grown SWCNTs. In particular, we will discuss the role of the growth temperature and the chemical composition of the catalyst on the final SWCNTs structure. The obtained SWCNTs are mainly characterized by Raman spectroscopy and electronic microscopy.In order to validate the observations performed by Raman measurement, the synthesized SWCNTs have been also integrated in field effect transistors (FET) devices. An analysis of the performance of the FET-device as a function of the SWCNTs used in its channel will be presented.Finally, SWCNTs integrated in these transistors have been functionalized with an inorganic chromophore of ruthenium.We demonstrate that the functionalization of the SWCNTs leads to a three order of magnitude reversible switch of the device conductivity triggered by visible light
Capítulos de libros sobre el tema "Carbone nanotubes microwave device"
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Ling, Yong-Chien y Archana Deokar. "Microwave-Assisted Preparation of Carbon Nanotubes with Versatile Functionality". En Carbon Nanotubes Applications on Electron Devices. InTech, 2011. http://dx.doi.org/10.5772/18720.
Texto completoActas de conferencias sobre el tema "Carbone nanotubes microwave device"
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Al Ahmad, Mahmoud, Abbes Tahraoui, W. I. Milne y Robert Plana. "Metallic multiwalled carbon nanotubes for microwave applications". En 2007 International Semiconductor Device Research Symposium. IEEE, 2007. http://dx.doi.org/10.1109/isdrs.2007.4422424.
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Brun, C., C. C. Yap, Stephane Bila, D. Baillargeat y B. K. Tay. "Measurement and modeling of carbon nanotubes-based flip-chip RF device". En 2013 IEEE/MTT-S International Microwave Symposium - MTT 2013. IEEE, 2013. http://dx.doi.org/10.1109/mwsym.2013.6697486.
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Gupta, S., N. Al Moayed, U. Khan, M. Obol y M. Afsar. "Complex permittivity and permeability of single- and multi-walled carbon nanotubes at high microwave frequencies and quantifying microwave absorption". En 2007 International Semiconductor Device Research Symposium. IEEE, 2007. http://dx.doi.org/10.1109/isdrs.2007.4422394.
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Hudanski, L., E. Minoux, L. Gangloff, K. B. K. Teo, J.-P. Schnell, S. Xavier, P. Legagneux y W. I. Milne. "Carbon nanotube based photocathode for microwave devices". En 2007 IEEE 20th International Vacuum Nanoelectronics Conference. IEEE, 2007. http://dx.doi.org/10.1109/ivnc.2007.4480940.
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Maschmann, Matthew R., Placidus B. Amama y Timothy S. Fisher. "Effect of DC Bias on Microwave Plasma Enhanced Chemical Vapor Deposition Synthesis of Single-Walled Carbon Nanotubes". En ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79007.
Texto completoResumen
The physical properties of carbon nanotubes (CNTs) make them outstanding candidates for introduction into technologies ranging from high resolution flat panel displays to nanoscale transistors. Integration of carbon nanotubes into devices, however, requires precise control over the manufacturing processes used during their synthesis. To meet the specific requirements of a given application, alignment, diameter, length and chirality of carbon nanotubes must be strictly addressed. This work demonstrates the controlled synthesis of single-walled carbon nanotubes (SWCNTs) with low amount of undesired carbonaceous species using plasma enhanced chemical vapor deposition (PECVD). This report elucidates the role of DC bias applied to the growth substrate during synthesis, including the field-enhanced alignment of SWCNTs, selectivity in the diameter distribution and selectivity of semiconducting versus metallic nanotubes. Carbon nanotubes are characterized using Raman spectroscopy and electron microscopy.
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Chung, Max, Bohr Ran Huang y Chih Chia Chang. "Carbon Nanotube Metal Cathode for Microwave and mm Wave Device". En 2007 IEEE Pulsed Power Plasma Science Conference. IEEE, 2007. http://dx.doi.org/10.1109/ppps.2007.4345480.
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Chung, Max, Chih Chia Chang, Bohr Ran Huang y Shiaw Hwei Cheng. "Small carbon nanotube cold field emission source for microwave device". En 2009 European Microwave Conference (EuMC). IEEE, 2009. http://dx.doi.org/10.23919/eumc.2009.5296551.
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Gyu-Young Son, Kun-Hong Lee y Yongshik Lee. "Synthesis of carbon nanotubes by direct irradiation of microwave signal". En 2006 IEEE Nanotechnology Materials and Devices Conference. IEEE, 2006. http://dx.doi.org/10.1109/nmdc.2006.4388874.
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Dragoman, M., D. Dragoman, M. Al Ahmad, R. Plana y E. Flahaut. "RF devices written with carbon nanotube ink on paper". En 2009 European Microwave Conference (EuMC). IEEE, 2009. http://dx.doi.org/10.23919/eumc.2009.5295991.
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Rai, Padmnabh, Dipti Ranjan Mohapatra, Abha Misra y D. S. Misra. "Field emission from carbon nanotubes: a comparative study between the carbon nanotubes synthesized by thermal and microwave plasma chemical vapor deposition". En 2007 International Workshop on Physics of Semiconductor Devices. IEEE, 2007. http://dx.doi.org/10.1109/iwpsd.2007.4472649.
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