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Liangyao Chen - One of the best experts on this subject based on the ideXlab platform.
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electronic properties and Bonding Configuration at the tin mgo 001 interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.
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Electronic properties and Bonding Configuration at the TiN/MgO(001) interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Xiao-ding Ma, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.
A Hoffman - One of the best experts on this subject based on the ideXlab platform.
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incorporation of nitrogen into polycrystalline diamond surfaces by rf plasma nitridation process at different temperatures Bonding Configuration and thermal stabilty studies by in situ xps and hreels
Physica Status Solidi (a), 2015Co-Authors: Maneesh Chandran, R Akhvlediani, Michal Shasha, Shaul Michaelson, A HoffmanAbstract:In situ studies of low energy nitrogen species incorporated into diamond films are significant as they could lead to a better understanding of Bonding Configuration and defects formation of the modified surface. In this report, we investigate the interaction of radio frequency (RF) nitrogen plasma onto a polycrystalline diamond surface at different temperatures (RT, 250, 500, and 750 °C). The influence of RF nitridation temperature on the Bonding Configuration, thermal stability, and concentrations of incorporated species were systematically investigated by in situ X-ray photoelectron spectroscopy and high resolution electron energy loss spectroscopy (HREELS). Our results showed that local Bonding Configurations were influenced by the temperature of the RF nitridation process. The amount of nitrogen incorporated into the diamond surface decreased as the nitridation process temperature increases. RF nitridation performed at 750 °C showed the absence of reorganization in the local Bonding Configurations upon annealing to 1000 °C and their thermal stability was also found to be better. HREELS results displayed partial retrieval of the characteristic optical phonon overtone of diamond, after annealing to 500 °C, which indicates that the RF nitridation process was successful in incorporating nitrogen into diamond surface without inducing a graphitic near surface region.
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hr eels study of hydrogen Bonding Configuration chemical and thermal stability of detonation nanodiamond films
Applied Surface Science, 2014Co-Authors: Sh Michaelson, R Akhvlediani, Tristan Petit, Hugues A Girard, J C Arnault, A HoffmanAbstract:Abstract Nano-diamond films composed of 3–10 nm grains prepared by the detonation method and deposited onto silicon substrates by drop-casting were examined by high resolution electron energy loss spectroscopy (HR-EELS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS). The impact of (i) ex-situ ambient annealing at 400 °C and (ii) ex-situ hydrogenation on hydrogen Bonding and its thermal stability were examined. In order to clarify the changes in hydrogen Bonding Configuration detected on the different surfaces as a function of thermal annealing, in-situ hydrogenation by thermally activated atomic hydrogen was performed and examined. This study provides direct evidence that the exposure to ambient conditions and medium temperature ambient annealing have a pronounced effect on the hydrogen-carbon Bonding Configuration onto the nano-diamond surfaces. In-situ 1000 °C annealing results in irreversible changes of the film surface and partial nano-diamond silicidation.
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hydrogen Bonding Configuration and thermal stability of ambient exposed and in situ hydrogenated polycrystalline diamond surfaces studied by high resolution electron energy loss spectroscopy
Physical Chemistry Chemical Physics, 2011Co-Authors: Sh Michaelson, R Akhvlediani, A HoffmanAbstract:In this work we report on an investigation of hydrogen Bonding and thermal stability on the surface of poly-crystalline diamond by high resolution electron energy loss spectroscopy (HR-EELS). Diamond films were grown on silicon substrates from CH4/H2 as well as from CD4/D2 gas mixtures by hot filament chemical vapor deposition (HF-CVD). The impact of ex situ ambient exposure on hydrogen Bonding and its thermal stability was examined for: (i) as deposited films from a CH4/H2 gas mixture; (ii) the same sample treated ex situ in micro-wave activated hydrogen plasma; and (iii) as deposited films from a CD4/D2 gas mixture. In order to clarify the changes in the hydrogen Bonding Configuration detected on the different surfaces as a function of thermal annealingin situhydrogenation by thermally activated atomic hydrogen was performed and examined. This study provides direct evidence that the exposure to ambient conditions and low temperature vacuum annealing have a pronounced effect on the hydrogen–carbon Bonding Configuration onto the poly-crystalline diamond surfaces.
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the impact of diamond grain size on hydrogen concentration Bonding Configuration and electron emission properties of polycrystalline diamond films
Chemical Vapor Deposition, 2008Co-Authors: Shaul Michaelson, R Akhvlediani, O Ternyak, A HoffmanAbstract:In the present work we review our recent studies of the incorporation of hydrogen and its Bonding Configuration in diamond films composed of diamond grains of varying size. Polycrystalline-diamond films are deposited by three different methods; hot filament (HF), microwave (MW) and direct current glow discharge (DCGD)CVD. The size of the diamond grains which constitute the films varies in the following way; hundreds of nanometers in the case of HFCVD (“sub-micrometer size”, ∼300 nm), tens of nanometers in the case of MWCVD (3–30 nm), and a few nanometers in the case of DCGDCVD (“ultra nanocrystalline diamond”, ∼5 nm). Raman spectroscopy (RS), secondary ion mass spectroscopy (SIMS), and high-resolution electron energy loss spectroscopy (HREELS) are applied to investigate the hydrogen trapping in the films. The hydrogen retention of the diamond films increases with decreasing grain size, indicating the likelihood that hydrogen is bonded and trapped in grain boundaries, as well as on the internal grain surfaces. RS and HREELS analyses show that at least part of this hydrogen is bonded to sp2- and sp3-hybridized carbon, thus giving rise to typical CH vibration modes. Both vibrational spectroscopies show the increase of sp2 CH modes in transition from sub-micrometer to ultra nanocrystalline grain size. The impact of diamond grain size on the shape of the RS and HREELS hydrogenated diamond spectra is discussed. In addition, the dependence of electron emission properties on film thickness and diamond grain size is reported.
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hydrogen concentration and Bonding Configuration in polycrystalline diamond films from micro to nanometric grain size
Journal of Applied Physics, 2007Co-Authors: Sh Michaelson, R Akhvlediani, A Hoffman, O Ternyak, A Lafosse, R Azria, Oliver Aneurin Williams, D M GruenAbstract:The present work studies the incorporation of hydrogen and its Bonding Configuration in diamond films composed of diamond grains of varying size which were deposited by three different methods: hot filament (HF), microwave (MW), and direct current glow discharge (dc GD) chemical vapor deposition (CVD). The size of diamond grains which constitute the films varies in the following way: hundreds of nanometers in the case of HF CVD (“submicron size,” ∼300nm), tens of nanometers in the case of MW CVD (3–30nm), and a few nanometers in the case of dc GD CVD (“ultrananocrystalline diamond,” ∼5nm). Raman spectroscopy, secondary ion mass spectroscopy, and high resolution electron energy loss spectroscopy (HR-EELS) were applied to investigate the hydrogen trapping in the films. The hydrogen retention of the diamond films increases with decreasing grain size, indicating that most likely, hydrogen is bonded and trapped in grain boundaries as well as on the internal grain surfaces. Raman and HR-EELS analyses show that ...
D Chen - One of the best experts on this subject based on the ideXlab platform.
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electronic properties and Bonding Configuration at the tin mgo 001 interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.
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Electronic properties and Bonding Configuration at the TiN/MgO(001) interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Xiao-ding Ma, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.
Sh Michaelson - One of the best experts on this subject based on the ideXlab platform.
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hr eels study of hydrogen Bonding Configuration chemical and thermal stability of detonation nanodiamond films
Applied Surface Science, 2014Co-Authors: Sh Michaelson, R Akhvlediani, Tristan Petit, Hugues A Girard, J C Arnault, A HoffmanAbstract:Abstract Nano-diamond films composed of 3–10 nm grains prepared by the detonation method and deposited onto silicon substrates by drop-casting were examined by high resolution electron energy loss spectroscopy (HR-EELS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS). The impact of (i) ex-situ ambient annealing at 400 °C and (ii) ex-situ hydrogenation on hydrogen Bonding and its thermal stability were examined. In order to clarify the changes in hydrogen Bonding Configuration detected on the different surfaces as a function of thermal annealing, in-situ hydrogenation by thermally activated atomic hydrogen was performed and examined. This study provides direct evidence that the exposure to ambient conditions and medium temperature ambient annealing have a pronounced effect on the hydrogen-carbon Bonding Configuration onto the nano-diamond surfaces. In-situ 1000 °C annealing results in irreversible changes of the film surface and partial nano-diamond silicidation.
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hydrogen Bonding Configuration and thermal stability of ambient exposed and in situ hydrogenated polycrystalline diamond surfaces studied by high resolution electron energy loss spectroscopy
Physical Chemistry Chemical Physics, 2011Co-Authors: Sh Michaelson, R Akhvlediani, A HoffmanAbstract:In this work we report on an investigation of hydrogen Bonding and thermal stability on the surface of poly-crystalline diamond by high resolution electron energy loss spectroscopy (HR-EELS). Diamond films were grown on silicon substrates from CH4/H2 as well as from CD4/D2 gas mixtures by hot filament chemical vapor deposition (HF-CVD). The impact of ex situ ambient exposure on hydrogen Bonding and its thermal stability was examined for: (i) as deposited films from a CH4/H2 gas mixture; (ii) the same sample treated ex situ in micro-wave activated hydrogen plasma; and (iii) as deposited films from a CD4/D2 gas mixture. In order to clarify the changes in the hydrogen Bonding Configuration detected on the different surfaces as a function of thermal annealingin situhydrogenation by thermally activated atomic hydrogen was performed and examined. This study provides direct evidence that the exposure to ambient conditions and low temperature vacuum annealing have a pronounced effect on the hydrogen–carbon Bonding Configuration onto the poly-crystalline diamond surfaces.
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hydrogen concentration and Bonding Configuration in polycrystalline diamond films from micro to nanometric grain size
Journal of Applied Physics, 2007Co-Authors: Sh Michaelson, R Akhvlediani, A Hoffman, O Ternyak, A Lafosse, R Azria, Oliver Aneurin Williams, D M GruenAbstract:The present work studies the incorporation of hydrogen and its Bonding Configuration in diamond films composed of diamond grains of varying size which were deposited by three different methods: hot filament (HF), microwave (MW), and direct current glow discharge (dc GD) chemical vapor deposition (CVD). The size of diamond grains which constitute the films varies in the following way: hundreds of nanometers in the case of HF CVD (“submicron size,” ∼300nm), tens of nanometers in the case of MW CVD (3–30nm), and a few nanometers in the case of dc GD CVD (“ultrananocrystalline diamond,” ∼5nm). Raman spectroscopy, secondary ion mass spectroscopy, and high resolution electron energy loss spectroscopy (HR-EELS) were applied to investigate the hydrogen trapping in the films. The hydrogen retention of the diamond films increases with decreasing grain size, indicating that most likely, hydrogen is bonded and trapped in grain boundaries as well as on the internal grain surfaces. Raman and HR-EELS analyses show that ...
Y M Wang - One of the best experts on this subject based on the ideXlab platform.
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electronic properties and Bonding Configuration at the tin mgo 001 interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.
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Electronic properties and Bonding Configuration at the TiN/MgO(001) interface
Physical Review B, 2004Co-Authors: D Chen, Y M Wang, Xiao-ding Ma, Liangyao ChenAbstract:Growth modes of a TiN thin film, epitaxially grown on MgO(001) substrate, have been proposed on the basis of transmission electron microscopic observation and theoretical calculations. The first-principle plane wave pseudopotential method, based on density functional theory, is applied to calculate electronic properties and Bonding Configurations at the interface. The theoretical calculations within framework of the observed orientation relationships show that cation-anion Bonding across the TiN/MgO(001) interface is favorable. Interfacial structures for this heteroepitaxial system have been established.