The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

E. Obermeier - One of the best experts on this subject based on the ideXlab platform.

  • Elastic properties of thin polycrystalline Diamond Films
    Diamond and Related Materials, 1993
    Co-Authors: M. Werner, S. Hein, E. Obermeier
    Abstract:

    Abstract Young's modulus, the shear modulus and Poisson's ratio of single-crystal Diamonds were calculated on the basis of the elastic coefficients as a function of the crystal orientation. The corresponding parameters for polycrystalline Diamond Films are obtained by averaging for all the crystal orientations. A value of 1143 GPa is obtained for Young's modulus of polycrystalline Diamond. The influence of the deposition temperature on the thermal stress was determined by finite element method simulations. The results show that, for Diamond Films deposited on silicon, the thermal stress always leads to compressive stress and amounts to a maximum of 663 GPa at a deposition temperature of 1100 K. The stress decreases with increasing thickness of the film.

Akira Hirose - One of the best experts on this subject based on the ideXlab platform.

  • Field electron emission characteristics of chemical vapour deposition Diamond Films with controlled sp2 phase concentration
    Thin Solid Films, 2008
    Co-Authors: Qiaoqin Yang, Chijin Xiao, Akira Hirose
    Abstract:

    Abstract Diamond Films were synthesized in a microwave plasma-enhanced chemical vapour deposition reactor. The microstructure and surface morphology of deposited Films were characterized by Raman spectroscope and scanning electron microscope. The sp 2 phase concentration in Diamond Films was varied and its effect on the field electron emission (FEE) properties was investigated. Diamond Films deposited under higher methane concentration exhibit better FEE property including lower turn-on electric field and larger emission current. The predominating factor modifying the FEE property is presumed to be the increase of sp 2 phase concentration. The influence of bias voltage on the FEE property of Diamond Films is not monotonic. Postgrowth acid treatment reduces the sp 2 phase content in Diamond Films without changing Diamond grain sizes. The corresponding FEE property was degraded.

  • direct coating of nanophase Diamond Films on steel substrate
    Chemical Physics Letters, 2006
    Co-Authors: Akira Hirose
    Abstract:

    Abstract This study reports on a successful deposition of adherent nanocrystalline Diamond Films on Fe–9Cr steel which is free of interlayer and pre-treatment, but has been alloyed with a small fraction of Al and Si (2.2 wt% each). High nucleation density and enhanced adhesion of Diamond Films have been achieved on the modified steel substrate. We have clarified the mechanism regarding the chemical nature of the steels and the Diamond Films formed.

Namas Chandra - One of the best experts on this subject based on the ideXlab platform.

  • Thermal characterization of Diamond Films through modulated photothermal radiometry.
    ACS Applied Materials & Interfaces, 2014
    Co-Authors: Thomas Guillemet, Andrzej Kusiak, Lisha Fan, Jean-marc Heintz, Namas Chandra, Yunshen Zhou, Jean-françois Silvain, Jean-luc Battaglia, Feng Lu Yong
    Abstract:

    Diamond (Dia) Films are promising heat-dissipative materials for electronic packages because they combine high thermal conductivity with high electrical resistivity. However, precise knowledge of the thermal properties of the Diamond Films is crucial to their potential application as passive thermal management substrates in electronics. In this study, modulated photothermal radiometry in a front-face configuration was employed to thermally characterize polycrystalline Diamond Films deposited onto silicon (Si) substrates through laser-assisted combustion synthesis. The intrinsic thermal conductivity of Diamond Films and the thermal boundary resistance at the interface between the Diamond film and the Si substrate were investigated. The results enlighten the correlation between the deposition process, film purity, film transverse thermal conductivity, and interface thermal resistance.

  • Stress and phase purity analyses of Diamond Films deposited through laser-assisted combustion synthesis
    ACS Applied Materials & Interfaces, 2011
    Co-Authors: Thomas Guillemet, Jean-marc Heintz, Jean-françois Silvain, Z. Q. Xie, Y. S. Zhou, J. B. Park, Amélie Veillere, W. Xiong, Namas Chandra
    Abstract:

    Diamond Films were deposited on silicon and tungsten carbide substrates in open air through laser-assisted combustion synthesis. Laser-induced resonant excitation of ethylene molecules was achieved in the combustion process to promote Diamond growth rate. In addition to microstructure study by scanning electron microscopy, Raman spectroscopy was used to analyze the phase purity and residual stress of the Diamond Films. High-purity Diamond Films were obtained through laser-assisted combustion synthesis. The levels of residual stress were in agreement with corresponding thermal expansion coefficients of Diamond, silicon, and tungsten carbide. Diamond-film purity increases while residual stress decreases with an increasing film thickness. Diamond Films deposited on silicon substrates exhibit higher purity and lower residual stress than those deposited on tungsten carbide substrates.

Thomas Guillemet - One of the best experts on this subject based on the ideXlab platform.

  • Thermal characterization of Diamond Films through modulated photothermal radiometry.
    ACS Applied Materials & Interfaces, 2014
    Co-Authors: Thomas Guillemet, Andrzej Kusiak, Lisha Fan, Jean-marc Heintz, Namas Chandra, Yunshen Zhou, Jean-françois Silvain, Jean-luc Battaglia, Feng Lu Yong
    Abstract:

    Diamond (Dia) Films are promising heat-dissipative materials for electronic packages because they combine high thermal conductivity with high electrical resistivity. However, precise knowledge of the thermal properties of the Diamond Films is crucial to their potential application as passive thermal management substrates in electronics. In this study, modulated photothermal radiometry in a front-face configuration was employed to thermally characterize polycrystalline Diamond Films deposited onto silicon (Si) substrates through laser-assisted combustion synthesis. The intrinsic thermal conductivity of Diamond Films and the thermal boundary resistance at the interface between the Diamond film and the Si substrate were investigated. The results enlighten the correlation between the deposition process, film purity, film transverse thermal conductivity, and interface thermal resistance.

  • Stress and phase purity analyses of Diamond Films deposited through laser-assisted combustion synthesis
    ACS Applied Materials & Interfaces, 2011
    Co-Authors: Thomas Guillemet, Jean-marc Heintz, Jean-françois Silvain, Z. Q. Xie, Y. S. Zhou, J. B. Park, Amélie Veillere, W. Xiong, Namas Chandra
    Abstract:

    Diamond Films were deposited on silicon and tungsten carbide substrates in open air through laser-assisted combustion synthesis. Laser-induced resonant excitation of ethylene molecules was achieved in the combustion process to promote Diamond growth rate. In addition to microstructure study by scanning electron microscopy, Raman spectroscopy was used to analyze the phase purity and residual stress of the Diamond Films. High-purity Diamond Films were obtained through laser-assisted combustion synthesis. The levels of residual stress were in agreement with corresponding thermal expansion coefficients of Diamond, silicon, and tungsten carbide. Diamond-film purity increases while residual stress decreases with an increasing film thickness. Diamond Films deposited on silicon substrates exhibit higher purity and lower residual stress than those deposited on tungsten carbide substrates.

M. Werner - One of the best experts on this subject based on the ideXlab platform.

  • Elastic properties of thin polycrystalline Diamond Films
    Diamond and Related Materials, 1993
    Co-Authors: M. Werner, S. Hein, E. Obermeier
    Abstract:

    Abstract Young's modulus, the shear modulus and Poisson's ratio of single-crystal Diamonds were calculated on the basis of the elastic coefficients as a function of the crystal orientation. The corresponding parameters for polycrystalline Diamond Films are obtained by averaging for all the crystal orientations. A value of 1143 GPa is obtained for Young's modulus of polycrystalline Diamond. The influence of the deposition temperature on the thermal stress was determined by finite element method simulations. The results show that, for Diamond Films deposited on silicon, the thermal stress always leads to compressive stress and amounts to a maximum of 663 GPa at a deposition temperature of 1100 K. The stress decreases with increasing thickness of the film.