Academic literature on the topic 'Amorphous-amorphous interfaces'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Amorphous-amorphous interfaces.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Amorphous-amorphous interfaces"

1

Huang, L., Z. Q. Chen, W. B. Liu, P. Huang, X. K. Meng, K. W. Xu, F. Wang, and T. J. Lu. "Enhanced irradiation resistance of amorphous alloys by introducing amorphous/amorphous interfaces." Intermetallics 107 (April 2019): 39–46. http://dx.doi.org/10.1016/j.intermet.2019.01.007.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Chu, V., M. Fang, and B. Drevillon. "Insituellipsometric study of amorphous silicon/amorphous silicon‐carbon interfaces." Journal of Applied Physics 69, no. 5 (March 1991): 3363–65. http://dx.doi.org/10.1063/1.348534.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wei, Shaosheng, Xiaohua Yu, and Dehong Lu. "First-Principles Calculation of the Bonding Strength of the Al2O3-Fe Interface Enhanced by Amorphous Na2SiO3." Materials 15, no. 13 (June 22, 2022): 4415. http://dx.doi.org/10.3390/ma15134415.

Full text
Abstract:
In this paper, the interfacial adhesion work (Wad), tensile strength, and electronic states of the Fe-amorphous Na2SiO3-Al2O3 and Fe-Al2O3 interfaces are well-investigated, utilizing the first-principles calculations. The results indicate that the Fe-amorphous Na2SiO3-Al2O3 interface is more stable and wettable than the interface of Fe-Al2O3. Specifically, the interfacial adhesion work of the Fe-amorphous Na2SiO3 interface is 434.89 J/m2, which is about forty times that of the Fe-Al2O3 interface, implying that the addition of amorphous Na2SiO3 promotes the dispersion of Al2O3 particle-reinforced. As anticipated, the tensile stress of the Fe-amorphous Na2SiO3-Al2O3 interface is about 46.58 GPa over the entire critical strain range, which is significantly greater than the Fe-Al2O3 interface control group. It could be inferred that the wear resistance of Al2O3 particle-reinforced is improved by adding amorphous Na2SiO3. To explain the electronic origin of this excellent performance, the charge density and density of states are investigated and the results indicate that the O atom in amorphous Na2SiO3 has a bonding action with Fe and Al; the amorphous Na2SiO3 acts as a sustained release. This study provides new ideas for particle-reinforced composites.
APA, Harvard, Vancouver, ISO, and other styles
4

Césari, C., G. Nihoul, J. Marfaing, W. Marine, and B. Mutaftschiev. "Amorphous-crystalline interfaces after laser induced explosive crystallization in amorphous germanium." Surface Science Letters 162, no. 1-3 (October 1985): A613. http://dx.doi.org/10.1016/0167-2584(85)90329-9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Césari, C., G. Nihoul, J. Marfaing, W. Marine, and B. Mutaftschiev. "Amorphous-crystalline interfaces after laser induced explosive crystallization in amorphous germanium." Surface Science 162, no. 1-3 (October 1985): 724–30. http://dx.doi.org/10.1016/0039-6028(85)90972-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Cheng, Z. Y., Jing Zhu, X. H. Liu, Xi Wang, and G. Q. Yang. "Microstructure of TiN films and interfaces formed by ion-beam-enhanced deposition and simple physical vapor deposition." Journal of Materials Research 10, no. 4 (April 1995): 995–99. http://dx.doi.org/10.1557/jmr.1995.0995.

Full text
Abstract:
The microstructure and composition of TiN films, formed by ion beam enhanced deposition (IBED) with different energy (40 keV and 90 keV) xenon ion bombardment and by simple physical vapor deposition (hereafter S-PVD) without any ion beam enhancement, and the interfaces between TiN films and Si substrates have been studied by cross-sectional view analytical electron microscopy in this work. Both the IBED TiN films prepared by Xe+ bombardment with either 40 keV or 90 keV energy ions and the S-PVD TiN film consist of nanocrystals. The TEM observations in the S-PVD case reveal an amorphous layer and a mixed layer of TiN grains and amorphous material at the TiN/Si interface. The thicknesses of the amorphous layer and the mixed layer are about 210 nm and at least 40 nm, respectively. Upon 40 keV Xe+ bombardment, an amorphous Si transition layer of about 50 nm thickness is found at the TiN/Si interface, and the TiN grains close to the TiN/Si interface are of weak preferred orientation. Upon 90 keV Xe+ bombardment, amorphous TiN and Si layers are found with a total thickness of 80 nm at the TiN/Si interface, and the TiN grains near the TiN/Si interface are of preferred orientation [111]TiN ‖ [001]Si. The energy of xenon ion bombardment has a strong effect on the microstructural characteristics of TiN films and the interfaces between the TiN films and the Si substrates, as well as the size and the preferred orientation of TiN grains.
APA, Harvard, Vancouver, ISO, and other styles
7

Roy, M., P. Sengupta, A. K. Tyagi, and G. B. Kale. "Investigations on Silicon/Amorphous-Carbon and Silicon/Nanocrystalline Palladium/Amorphous-Carbon Interfaces." Journal of Nanoscience and Nanotechnology 8, no. 8 (August 1, 2008): 4295–302. http://dx.doi.org/10.1166/jnn.2008.an37.

Full text
Abstract:
Our previous work revealed that significant enhancement in sp3-carbon content of amorphous carbon films could be achieved when grown on nanocrystalline palladium interlayer as compared to those grown on bare silicon substrates. To find out why, the nature of interface formed in both the cases has been investigated using Electron Probe Micro Analysis (EPMA) technique. It has been found that a reactive interface in the form of silicon carbide and/silicon oxy-carbide is formed at the interface of silicon/amorphous-carbon films, while palladium remains primarily in its native form at the interface of nanocrystalline palladium/amorphous-carbon films. However, there can be traces of dissolved oxygen within the metallic layer as well. The study has been corroborated further from X-ray photoelectron spectroscopic studies.
APA, Harvard, Vancouver, ISO, and other styles
8

Herth, S., H. Rösner, A. A. Rempel, H. E. Schaefer, and R. Würschum. "Positrons as chemically sensitive probes in interfaces of multicomponent complex materials: Nanocrystalline Fe90Zr7B3." International Journal of Materials Research 94, no. 10 (October 1, 2003): 1073–78. http://dx.doi.org/10.1515/ijmr-2003-0196.

Full text
Abstract:
Abstract The present paper reports on a combined analytical and structural study of nanocrystalline Fe90Zr7B3 by means of positron annihilation, (analytical) high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction. Particular focus is laid on the chemical nature of the intergranular amorphous matrix which occurs between the α-Fe nanocrystallites. Energy-dispersive X-ray measurements (EDX) with an electron nanobeam reveal an increased Zr content at the interface between the nanocrystallites and the intergranular amorphous phase. According to positron lifetime measurements, the intergranular amorphous phase and the interfaces between this phase and the nanocrystallites exhibit structural free volumes of the mean size slightly smaller than a lattice vacancy as in the amorphous precursor material. Coincident Doppler broadening measurements of the positron-electron annihilation photons show that the fraction of Zr in the neighborhood of the structural free volumes is higher in nanocrystalline Fe90Zr7B3 than in the amorphous state indicating an enhanced Zr concentration in the interfaces. These results are in good agreement with the HRTEM/ EDX studies and demonstrate the potentials of the coincident Doppler broadening technique for a chemical characterization of structurally complex materials on an atomistic scale.
APA, Harvard, Vancouver, ISO, and other styles
9

Hohensee, Gregory T., Mousumi M. Biswas, Ella Pek, Chris Lee, Min Zheng, Yingmin Wang, and Chris Dames. "Pump-probe thermoreflectance measurements of critical interfaces for thermal management of HAMR heads." MRS Advances 2, no. 58-59 (2017): 3627–36. http://dx.doi.org/10.1557/adv.2017.503.

Full text
Abstract:
ABSTRACT For heat-assisted magnetic recording (HAMR) heads, a major reliability limiter is the peak near-field transducer (NFT) temperature. Since the NFT is nanoscale, heat sinking is controlled by materials and interfaces within a few 100 nm of the NFT. Heat sinks can be metallic to take advantage of the 10x-100x higher thermal boundary conductance (TBC) of metal/metal interfaces, versus nonmetal interfaces. Oxide formation at these interfaces can greatly decrease the TBC and contribute to NFT failure. Likewise, the thermal resistance of material between the NFT and media recording layer greatly influences the NFT operating temperature. Here we use pump-probe thermoreflectance techniques (FDTR, TDTR) to study metal-metal interfaces and detect partial oxidation of a buried metallic thin film, as well as evaluate the interface thermal conductance of amorphous-amorphous interfaces in a film stack representative of a HAMR head-media interface.
APA, Harvard, Vancouver, ISO, and other styles
10

Avishai, Amir, Christina Scheu, and Wayne D. Kaplan. "Amorphous Films at Metal/Ceramic Interfaces." Zeitschrift für Metallkunde 94, no. 3 (March 2003): 272–76. http://dx.doi.org/10.3139/146.030272.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Amorphous-amorphous interfaces"

1

Kast, Matthew. "Towards Tunable and Multifunctional Interfaces: Multicomponent Amorphous Alloys and Bilayer Stacks." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22288.

Full text
Abstract:
Controlling the electronic structure and requisite charge transfer at and across interfaces is a grand challenge of materials science. Despite decades of research and numerous successes in the fields microelectronics and photovoltaics much work remains to be done. In many applications, whether they be in microelectronics, photovoltaics or display technology there is a demand for multiple functions at a single interface. Historically, existent materials were either discarded as an option due to known properties or tested with some application based figure of merit in mind. Following this, the quality of the material and/or the preparation of the surface/interface to which the material would be deposited was optimized. As the microelectronics and photovoltaics industries have matured, continued progress (faster, lower power transistors and more efficient, cheaper, abundant solar cells) will require new materials (possibly not previously existent) that are fundamentally better for their application than their highly optimized existent counter parts. The manifestation of this has been seen in the microelectronics field with introduction of hafnium silicates to replace silica (which had previously been monumentally successful) as the gate dielectrics for the most advanced transistors. Continued progress in efficient, cheap, abundant photovoltaics will require similar advances. Advances will be needed in the area of new abundant absorbers that can be deposited cheaply which result in materials with high efficiencies. In addition, selective contacts capable of extracting charge from efficient absorbers with low ohmic losses and low recombination rates will be needed. Presented here are two approaches to the multifunctional interface problem, first the use of amorphous alloys that open up the accessible composition space of thin films significantly and second the use of bilayers that loosen the requirements of a single film at an interface.
APA, Harvard, Vancouver, ISO, and other styles
2

Hassanali, Ali. "WATER AT MOLECULAR INTERFACES: STRUCTURE AND DYNAMICS NEAR BIOMOLECULES AND AMORPHOUS SILICA." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275314943.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Mews, Mathias [Verfasser], Bernd [Gutachter] Rech, i. Cabarrocas Pere [Gutachter] Roca, and Bernd [Gutachter] Szyszka. "Interfaces in amorphous/crystalline silicon heterojunction solar cells / Mathias Mews ; Gutachter: Bernd Rech, Pere Roca i Cabarrocas, Bernd Szyszka." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156181437/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Ross, Nick. "Interfacial Electrochemistry of Cu/Al Alloys for IC Packaging and Chemical Bonding Characterization of Boron Doped Hydrogenated Amorphous Silicon Films for Infrared Cameras." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849696/.

Full text
Abstract:
We focused on a non-cooling room temperature microbolometer infrared imaging array device which includes a sensing layer of p-type a-Si:H component layers doped with boron. Boron incorporation and bonding configuration were investigated for a-Si:H films grown by plasma enhanced chemical deposition (PECVD) at varying substrate temperatures, hydrogen dilution of the silane precursor, and dopant to silane ratio using multiple internal reflection infrared spectroscopy (MIR-IR). This study was then confirmed from collaborators via Raman spectroscopy. MIR-IR analyses reveal an interesting counter-balance relationship between boron-doping and hydrogen-dilution growth parameters in PECVD-grown a-Si:H. Specifically, an increase in the hydrogen dilution ratio (H2/SiH4) or substrate temperature was found to increase organization of the silicon lattice in the amorphous films. It resulted in the decrease of the most stable SiH bonding configuration and thus decrease the organization of the film. The new chemical bonding information of a-Si:H thin film was correlated with the various boron doping mechanisms proposed by theoretical calculations. The study revealed the corrosion morphology progression on aluminum alloy (Al, 0.5% Cu) under acidic chloride solution. This is due to defects and a higher copper content at the grain boundary. Direct galvanic current measurement, linear sweep voltammetry (LSV), and Tafel plots are used to measure corrosion current and potential. Hydrogen gas evolution was also observed (for the first time) in Cu/Al bimetallic interface in areas of active corrosion. Mechanistic insight that leads to effective prevention of aluminum bond pad corrosion is explored and discussed. (Chapter 4) Aluminum bond pad corrosion activity and mechanistic insight at a Cu/Al bimetallic interface typically used in microelectronic packages for automotive applications were investigated by means of optical and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and electrochemistry. Screening of corrosion variables (temperature, moisture, chloride ion concentration, pH) have been investigated to find their effect on corrosion rate and to better understand the Al/Cu bimetallic corrosion mechanism. The study revealed the corrosion morphology progression on aluminum alloy (Al, 0.5% Cu) under acidic chloride solution. The corrosion starts as surface roughening which evolves into a dendrite structure and later continues to grow into a mud-crack type corrosion. SEM showed the early stage of corrosion with dendritic formation usually occurs at the grain boundary. This is due to defects and a higher copper content at the grain boundary. The impact of copper bimetallic contact on aluminum corrosion was explored by sputtering copper microdots on aluminum substrate. Copper micropattern screening revealed that the corrosion is activated on the Al/Cu interface area and driven by the large potential difference; it was also seen to proceed at much higher rates than those observed with bare aluminum. Direct galvanic current measurement, linear sweep voltammetry (LSV), and Tafel plots are used to measure corrosion current and potential. Hydrogen gas evolution was also observed (for the first time) in Cu/Al bimetallic interface in areas of active corrosion. Mechanistic insight that leads to effective prevention of aluminum bond pad corrosion is explored and discussed. Micropattern corrosion screening identified hydrogen evolution and bimetallic interface as the root cause of Al pad corrosion that leads to Cu ball lift-off, a fatal defect, in Cu wire bonded device. Complete corrosion inhibition can be achieved by strategically disabling the mutually coupled cathodic and anodic reaction cycles.
APA, Harvard, Vancouver, ISO, and other styles
5

Lidbaum, Hans. "Transmission Electron Microscopy for Characterization of Structures, Interfaces and Magnetic Moments in Magnetic Thin Films and Multilayers." Doctoral thesis, Uppsala universitet, Experimentell fysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-107941.

Full text
Abstract:
Structural characterization is essential for the understanding of the magnetic properties of thin films and multilayers. In this thesis, both crystalline and amorphous thin films and multilayers were analyzed utilizing transmission electron microscopy (TEM). High resolution TEM and electron diffraction studies emphasize on the growth of amorphous Fe91Zr9 and Co68Fe24Zr8 on both Al2O3 and Al70Zr30 in multilayer structures by magnetron sputtering. The properties of the growth surfaces were found to strongly influence the formation of nano-crystallites of the magnetic material at interfaces. Field induced uniaxial magnetic anisotropy was found to be possible to imprint into both fully amorphous and partially crystallized Co68Fe24Zr8 layers, yielding similar magnetic characteristics regardless of the structure. These findings are important for the understanding of both growth and magnetic properties of these amorphous thin films. As magnetic systems become smaller, new analysis techniques need to be developed. One such important step was the realization of electron energy-loss magnetic circular dichroism (EMCD) in the TEM, where information about the ratio of the orbital to spin magnetic moment (mL/mS) of a sample can be obtained. EMCD makes use of angular dependent inelastic scattering, which is characterized using electron energy-loss spectroscopy. The work of this thesis contributes to the development of EMCD by performing quantitative measurements of the mL/mS ratio. Especially, methods for obtaining energy filtered diffraction patterns in the TEM together with analysis tools of the data were developed. It was found that plural inelastic scattering events modify the determination of the mL/mS ratio, wherefore a procedure to compensate for it was derived. Additionally, utilizing special settings of the electron gun it was shown that EMCD measurements becomes feasible on the nanometer level through real space maps of the EMCD signal.
APA, Harvard, Vancouver, ISO, and other styles
6

Fagas, Georgios. "Vibrational properties of complex solids." Thesis, Lancaster University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321898.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Varache, Renaud. "Development, characterization and modeling of interfaces for high efficiency silicon heterojunction solar cells." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112279/document.

Full text
Abstract:
L’interface entre le silicium amorphe (a-Si:H) et le silicium cristallin (c-Si) est un constituent clés de cellules solaires à haut rendement reposant sur des procédés à basse température. Trois propriétés de l’interface déterminent le rendement des cellules solaires à hétérojonction de silicium: les décalages de bandes entre a-Si:H et c-Si, les défauts d’interface et la courbure de bande dans c-Si. Ces trois aspects sont traités dans ces travaux de thèse.Dans un premier un temps, un calcul analytique de la courbure de bande dans c-Si est développé. Il repose sur l’approximation d’une densité d’état (DE) constante dans la bande interdite de a-Si:H. L’influence des principaux paramètres de la structure sur la courbure de bande est étudiée : décalage de bande, densité d’état dans a-Si:H, défaut d’interface, etc. La présence d’un effet de confinement quantique est discutée. Grâce à une comparaison entre ces calculs et des mesures de conductance planaire en fonction de la température sur des structures (p)a-Si:H/(n)c-Si et (n)a-Si:H/(p)c-Si, les décalages de bande de valence et de conduction ont pu être estimés à 0.36 eV et 0.15 eV respectivement. En outre, il est montré que le décalage de la bande de valence est indépendant de la température, alors que le décalage de la bande de conduction suit les évolutions des bandes interdites de c-Si et a-Si:H. Ces mesures tendent à prouver que le ‘branch point’ dans a-Si:H est indépendant du dopage.Ensuite, les calculs analytiques sont approfondis pour prendre en compte différents aspects de la structure complète incorporée dans les cellules : contact avec un oxyde transparent conducteur, présence d’une couche de a-Si:H non-dopée à l’interface. A l’aide de simulations numériques et à la lumière de mesures de conductance planaire conjuguées à des mesures de la qualité de passivation de l’interface, des pistes pour optimiser les cellules à hétérojonction sont commentées. En particulier, il est montré qu’un optimum doit être trouvé entre une bonne passivation et une courbure de bande suffisante. Ceci peut être accompli par un réglage fin des propriétés de la couche tampon (épaisseur, dopage), du contact (travail de sortie élevé) et de l’émetteur (p)a-Si:H (densité de défauts et épaisseur). En particulier, un émetteur avec une DE importante conduit paradoxalement à de meilleures performances.Enfin, un nouveau type d’interface a été développé. La surface de c-Si a été oxydée volontairement dans de l’eau pure dé-ionisée à 80 °C avant le dépôt de (p)a-Si:H afin d’obtenir une structure (p)a-Si:H/SiO2/(n)c-Si. A l’aide d’un modèle de courant par effet tunnel implémenté dans le logiciel de simulation numérique AFORS-HET, l’effet d’une couche à grande bande interdite (comme c’est le cas pour SiO2) sur les performances de cellules est étudié : le facteur de forme et le courant de court-circuit sont extrêmement réduits. En revanche, une couche de SiO2 n’a que peu d’impact sur les propriétés optiques de la structure. Expérimentalement, les échantillons réalisés montrent une qualité de passivation à mi-chemin entre le cas sans couche tampon et le cas avec (i)a-Si:H : ceci est expliqué par la présence d’une charge fixe négative dans l’oxyde. La courbure de bande dans c-Si est moins affectée par la présence d’une couche d’oxyde que d’une couche de (i)a-Si:H. Les cellules solaires réalisées démontrent que le concept a le potentiel d’aboutir à de hauts rendements : sur des structures non-optimisées, une tension de court-circuit supérieure à 650 mV a été démontrée, alors que l’oxyde ne semble pas limiter le transport de charge
The interface between amorphous silicon (a-Si:H) and crystalline silicon (c-Si) is the building block of high efficiency solar cells based on low temperature fabrication processes. Three properties of the interface determine the performance of silicon heterojunction solar cells: band offsets between a-Si:H and c-Si, interface defects and band bending in c-Si. These three points are addressed in this thesis.First, an analytical model for the calculation of the band bending in c-Si is developed. It assumes a constant density of states (DOS) in the a-Si:H band gap. The influence of most parameters of the structure on the band bending is studied: band offsets, DOS in a-Si:H, interface defects, etc. The presence of quantum confinement at the interface is discussed. Analytical calculations and temperature dependent planar conductance measurements are compared such that the band offsets on both (p)a-Si:H/(n)c-Si and (n)a-Si:H/(p)c-Si can be estimated: the valence band offset amounts 0.36 eV while the conduction band offset is 0.15 eV. In addition, it is shown that the valence band offset is independent of temperature whereas the conduction band offset follows the evolutions of c-Si and a-Si:H band gaps with temperature. A discussion of these results in the frame of the branch point theory for band line-up leads to the conclusion that the branch point in a-Si:H is independent of the doping.Then, analytical calculations are developed further to take into account the real solar cell structure where the a-Si:H/c-Si structure is in contact with a transparent conductive oxide and an undoped buffer layer is present at the interface. Measurements of the planar conductance and of the interface passivation quality are interpreted in the light of analytical calculations and numerical simulations to open a way towards a method for the optimization of silicon heterojunction solar cells. It is particularly shown that a trade-off has to be found between a good passivation quality and a significant band bending. This can be realized by tuning the buffer layer properties (thickness, doping), the TCO-contact (high work function) and the emitter (defect density and thickness). Interestingly, an emitter with a high DOS leads to better cell performances.Finally, a new type of interface has been developed, that was not applied to heterojunction solar cells so far. The c-Si surface has been oxidized in deionized water at 80 °C before the (p)a-Si:H emitter deposition such that (p)a-Si:H/SiO2/(n)c-Si structures were obtained. A tunneling current model has been developed, implemented in the 1D numerical device simulator AFORS-HET and used to study the effect of a wide band gap interfacial layer (as it is the case for SiO2) on cell performance: the fill-factor and the short-circuit current are dramatically reduced for thick and high barriers. However, a SiO2 layer has only little impact on optical properties. Fabricated samples show a passivation quality halfway between samples with no buffer layer and with an (i)a-Si:H buffer layer: this is explained by the presence of a negative fixed charge in the oxide. The band bending in (n)c-Si is higher with an oxide layer than with an (i)a-Si:H buffer layer. Solar cells demonstrate that this new concept has the potential to achieve high power conversion efficiencies: for non-optimized structures, an open-circuit voltage higher than 650 mV has been demonstrated, while the oxide does not seem to create a barrier to charge transport
APA, Harvard, Vancouver, ISO, and other styles
8

Luo, Haoming. "High frequency thermomechanical study of heterogeneous materials with interfaces." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI130.

Full text
Abstract:
Le transfert de chaleur est intimement lié à la propagation du son (transfert acoustique) dans les matériaux, par exemple dans les isolants et les semi-conducteurs, les principaux vecteurs d’énergie sont des phonons acoustiques. Le concept de présence d’interfaces a été largement exploité pour manipuler efficacement les phonons des longueurs d’onde macroscopiques aux longueurs d’onde nanométriques. Les derniers correspondent aux fréquences en régime THz, qui sont responsables du transport thermique à température ambiante. Dans cette thèse, la méthode des éléments finis est utilisée pour effectuer des analyses transitoires de la propagation des paquets d’ondes dans différents milieux à 2D. Elle est commencée par une étude paramétrique de l’atténuation des paquets d’ondes dans un système élastique semi-infini avec des interfaces circulaires périodiques. Trois paramètres clés sont étudiés, notamment le contraste de rigidité, la densité d’interface et la longueur d’onde des phonons. Différents régimes de transfert (propagatif, diffusif et localisé) sont identifiés, qui permettent d’identifier la contribution des phonons à la conductivité thermique. Outre les interfaces circulaires, la réponse mécanique et l’atténuation acoustique pour différents types d’interfaces sont également étudiées, telles que l’inclusion de forme dendritique, l’inclusion d’Eshelby, et les matériaux poreux avec des pores ordonnés / désordonnés. Afin d’étendre l’étude aux matériaux amorphes, j’ai également considéré un milieu hétérogène avec des rigidités aléatoires réparties dans l’espace selon une distribution gaussienne basée sur la théorie de l’élasticité de cisaillement hétérogène des verres. Enfin et surtout, deux versions de lois de comportement viscoélastiques sont proposées pour prendre en compte l’atténuation intrinsèque des phonons dépendant de la fréquence dans les verres, dans le but qu’un milieu visqueux homogène puisse reproduire cette atténuation intrinsèque. La simulation par éléments finis confirme qu’un modèle continu peut suivre strictement l’atténuation atomistique (G) avec une loi de comportement viscoélastique linéaire macroscopique bien calibrée. Par rapport aux données expérimentales de a-SiO2, notre deuxième loi de comportement reproduit qualitativement et quantitativement les trois régimes d’atténuation acoustique en fonction de la fréquence : successivement Γ ∝ ω^2,ω^4,ω^2
Heat transfer is actually intimately related to the sound propagation (acoustic transfer) in materials, as in insulators and semi-conductors the main heat carriers are acoustic phonons. The concept of the presence of interfaces has been largely exploited for efficiently manipulating phonons from long-wavelength to nanometric wavelengths, i.e., frequencies in THz regime, responsible for thermal transport at room temperature. In this thesis, the finite element method is used to perform transient analysis of wavepacket propagation in different mediums. I started with a parametric study of attenuation of acoustic wave-packets in a 2D semi-infinite elastic system with periodic circular interfaces. Three key parameters are investigated, including rigidity contrast, interface density and phonon wavelength. Different energy transfer regimes (propagative, diffusive, and localized) are identified allowing to understand the phonon contribution to thermal transport. Besides the circular interfaces, mechanical response and acoustic attenuation for different types of interfaces are also investigated, such as Eshelby’s inclusion, dendritic shape inclusion and porous materials with ordered/disordered holes. In order to extend the study to amorphous materials, I also considered a heterogeneous medium with random rigidities distributed in space according to a Gaussian distribution based on the theory of heterogeneous shear elasticity of glasses. Finally yet importantly, viscoelastic constitutive laws are proposed to take into account the frequency-dependent intrinsic phonon attenuation in glasses, with the aim of reproducing such intrinsic attenuation using a homogeneous viscous medium. Finite element simulation confirms that a continuum model may strictly follow the atomistic attenuation (G) for a well-calibrated macroscopic linear viscoelastic constitutive law. Compared with the experimental data in a-SiO2, our second constitutive law reproduces qualitatively and quantitatively the three regimes of acoustic attenuation versus frequency : successively Γ∝ω^2,ω^4,ω^2
APA, Harvard, Vancouver, ISO, and other styles
9

Zhu, Kai Schiff Eric A. "Interface modulation spectroscopy and doping physics in amorphous silicon." Related Electronic Resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2003. http://wwwlib.umi.com/cr/syr/main.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Gandy, Amy S. "A Transmission Electron Microscopy study of the Interaction between Defects in Amorphous Silicon and a Moving Crystalline/Amorphous Interface." Thesis, University of Salford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502784.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Amorphous-amorphous interfaces"

1

Wilfried G. J. H. M. Sark. Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2011.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sukirno. Ion beam induced interface motion and impurity relocation in amorphous layers on SI. Salford: University of Salford, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Amorphous-amorphous interfaces"

1

Blank-Bewersdorff, Margret, Uwe Köster, and Gabriele Bewernick. "Metallic Amorphous/Crystalline Interfaces." In Controlled Interphases in Composite Materials, 667–75. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-7816-7_61.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Herman, Frank, and Philippe Lambin. "Interfaces Between Crystalline and Amorphous Tetrahedrally Coordinated Semiconductors." In Tetrahedrally-Bonded Amorphous Semiconductors, 469–82. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-5361-2_40.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Chakraverty, B. K. "Dislocation Mediated Pseudo-Melting at Silicon-Metal Interfaces." In Physical Properties of Amorphous Materials, 261–75. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-2260-1_8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Schlapbach, Louis. "Hydrogen at Metallic Surfaces and Interfaces." In Hydrogen in Disordered and Amorphous Solids, 397–421. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4899-2025-6_33.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Tosi, M. P. "Liquid Surfaces and Solid-Liquid Interfaces." In Amorphous Solids and the Liquid State, 125–56. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4757-9156-3_5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Ravindra, N. M., D. Fathy, O. W. Holland, and J. Narayan. "Si — SiO2 Interfaces — a Hrtem Study." In The Physics and Technology of Amorphous SiO2, 279–83. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-1031-0_38.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Novio, Fernando, and Daniel Ruiz-Molina. "Coordination Polymers for Medical Applications: Amorphous versus Crystalline Materials." In Hybrid Organic-Inorganic Interfaces, 661–94. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2017. http://dx.doi.org/10.1002/9783527807130.ch15.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Wool, R. P. "Strength and Entanglement Development at Amorphous Polymer Interfaces." In The IMA Volumes in Mathematics and Its Applications, 169–87. New York, NY: Springer New York, 1987. http://dx.doi.org/10.1007/978-1-4612-1064-1_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Horbach, J., T. Stühn, C. Mischler, W. Kob, and K. Binder. "Amorphous Silica at Surfaces and Interfaces: Simulation Studies." In High Performance Computing in Science and Engineering ’03, 167–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-642-55876-4_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Jhon, Mu Shik, and Youngie Oh. "Interfacial Tensions at Amorphous High Polymer-Water Interfaces: Theory." In Surface and Interfacial Aspects of Biomedical Polymers, 395–420. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4684-8610-0_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Amorphous-amorphous interfaces"

1

Malyska, K., Ali Erdemir, Sergey A. Chizhik, Zygmunt Rymuza, and Lukasz Ratajczyk. "Amorphous Carbon Thin Films for Interfaces in MEMS." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63147.

Full text
Abstract:
Friction and nanoscratch tests were performed on amorphous carbon thin films deposited on silicon. The effect of process and conditions on CVD deposited films was studied. Coefficient of friction between the films was estimated by using a special oscillating microtribometer. The lateral force and maximum depth of scratching were measured during nanoscratch tests. The comparison of tribological behavior of the tested films is presented and discussed.
APA, Harvard, Vancouver, ISO, and other styles
2

Caputo, D., G. de Cesare, C. Manetti, A. Nascetti, and R. Scipinotti. "Chromatographic System Based on Amorphous Silicon Photodiodes." In 2nd IEEE International Workshop on Advances in Sensors and Interfaces, IWASI 2007. IEEE, 2007. http://dx.doi.org/10.1109/iwasi.2007.4420008.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Roy, Ajit K., V. Varshney, S. Ganguli, S. Sihn, J. Lee, and B. Farmer. "Atomistic Scale Thermal Transport in Amorphous Materials and Its Interfaces." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44656.

Full text
Abstract:
The thermal loads (excess heat) in all DoD systems (aircrafts and spacecrafts) have steadily been increasing at an alarming rate. The current practice is use fuel as the heat sink to dump the excess heat. This operational approach currently is not adequate to sufficiently cool the electronics and thermal devices, and thus limiting the system performance and its system readiness. Amorphous materials system (polymers, adhesive, etc.), which is known to be thermally non-conductive material, is prevalent in almost all DoD systems. So, there is a big incentive in tailoring its thermal transport characteristics to meet the system requirements. Advent of the conductive nano material constituents (such as, carbon nanotubes, graphite platelets, graphene, etc.) and its adaptation in polymers provides us such opportunity. The success of adapting the nano constituents in polymers in providing the conductive pathways through the polymer phase solely lies on the extent how the interface thermal transport characteristics are tailoring between the polymer and nano constituent interfaces. In order to understand the thermal transport phenomena is amorphous materials and to design its interface consistent to the nano constituent morphology scale, computational methodology using atomistic molecular dynamics (MD) is developed. Examples for tailoring thermal interface of nano constituents with polymer will be presented.
APA, Harvard, Vancouver, ISO, and other styles
4

Caputo, D., G. de Cesare, A. Nascetti, and R. Scipinotti. "Amorphous silicon balanced photodiode for application in biomolecular analysis." In 2009 3rd International Workshop on Advances in sensors and Interfaces. IEEE, 2009. http://dx.doi.org/10.1109/iwasi.2009.5184760.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Milinović, V., K. Zhang, N. Bibić, K. P. Lieb, M. Milosavljević, and P. K. Sahoo. "Ion Beam Mixing at Crystalline and Amorphous Fe/Si Interfaces." In THE PHYSICS OF IONIZED GASES: 23rd Summer School and International Symposium on the Physics of Ionized Gases; Invited Lectures, Topical Invited Lectures and Progress Reports. AIP, 2006. http://dx.doi.org/10.1063/1.2406030.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Nascetti, A., G. de Cesare, and D. Caputo. "Large area hybrid detector technology based on amorphous silicon photosensors." In 2009 3rd International Workshop on Advances in sensors and Interfaces. IEEE, 2009. http://dx.doi.org/10.1109/iwasi.2009.5184763.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Price, Michael, Andrey Ovcharenko, Raj Thangaraj, and Bart Raeymaekers. "Delamination of Ultra-Thin Diamond-Like Carbon Coatings on Magnetic Recording Heads Under Normal Loading." In ASME 2013 Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/isps2013-2899.

Full text
Abstract:
Delamination between an ultra-thin amorphous carbon overcoat, a silicon adhesion layer, and permalloy substrate material of a hard drive recording head is studied during normal loading/unloading of the head disk interface. The effect of normal load and thickness of the silicon adhesion layer on delamination of the Si-permalloy and amorphous carbon-Si interfaces is quantified using a molecular dynamics model. No permanent delamination is found for contact pressures up to 100 MPa, except for the case where a silicon adhesion layer is absent.
APA, Harvard, Vancouver, ISO, and other styles
8

Menichelli, M., L. Antognini, A. Bashiri, M. Bizzarri, L. Calcagnile, M. Caprai, A. P. Caricato, et al. "X-ray qualification of hydrogenated amorphous silicon sensors on flexible substrate." In 2023 9th International Workshop on Advances in Sensors and Interfaces (IWASI). IEEE, 2023. http://dx.doi.org/10.1109/iwasi58316.2023.10164611.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Munson, Kyle, and John B. Asbury. "Characterization of triplet separation and diffusion in amorphous pentacene films via ultrafast infrared spectroscopy." In Physical Chemistry of Semiconductor Materials and Interfaces XX, edited by Daniel Congreve, Christian Nielsen, Andrew J. Musser, and Derya Baran. SPIE, 2021. http://dx.doi.org/10.1117/12.2594600.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

de Cesare, Giampiero, Domenico Caputo, and Augusto Nascetti. "Simultaneous measurement of light and temperature by a single amorphous silicon sensor." In 2015 6th IEEE International Workshop on Advances in Sensors and Interfaces (IWASI). IEEE, 2015. http://dx.doi.org/10.1109/iwasi.2015.7184971.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Amorphous-amorphous interfaces"

1

Carter, C. B. Crystalline-amorphous interfaces and their relation to grain boundary films. Office of Scientific and Technical Information (OSTI), February 1992. http://dx.doi.org/10.2172/5738322.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Schiff, E. A. Transport, Interfaces, and Modeling in Amorphous Silicon Based Solar Cells: Final Technical Report, 11 February 2002 - 30 September 2006. Office of Scientific and Technical Information (OSTI), October 2008. http://dx.doi.org/10.2172/940635.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Carter, C. B. Crystalline-amorphous interfaces and their relation to grain boundary films. A report for the 3-year period, 15 November 1988--14 November 1991. Office of Scientific and Technical Information (OSTI), February 1992. http://dx.doi.org/10.2172/10131126.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Pisani, William, Dane Wedgeworth, Michael Roth, John Newman, and Manoj Shukla. Exploration of two polymer nanocomposite structure-property relationships facilitated by molecular dynamics simulation and multiscale modeling. Engineer Research and Development Center (U.S.), March 2023. http://dx.doi.org/10.21079/11681/46713.

Full text
Abstract:
Polyamide 6 (PA6) is a semi-crystalline thermoplastic used in many engineering applications due to good strength, stiffness, mechanical damping, wear/abrasion resistance, and excellent performance-to-cost ratio. In this report, two structure-property relationships were explored. First, carbon nanotubes (CNT) and graphene (G) were used as reinforcement molecules in simulated and experimentally prepared PA6 matrices to improve the overall mechanical properties. Molecular dynamics (MD) simulations with INTERFACE and reactive INTERFACE force fields (IFF and IFF-R) were used to predict bulk and Young's moduli of amorphous PA6-CNT/G nanocomposites as a function of CNT/G loading. The predicted values of Young's modulus agree moderately well with the experimental values. Second, the effect of crystallinity and crystal form (α/γ) on mechanical properties of semi-crystalline PA6 was investigated via a multiscale simulation approach. The National Aeronautics and Space Administration, Glenn Research Center's micromechanics software was used to facilitate the multiscale modeling. The inputs to the multiscale model were the elastic moduli of amorphous PA6 as predicted via MD and calculated stiffness matrices from the literature of the PA6 α and γ crystal forms. The predicted Young's and shear moduli compared well with experiment.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography