Search query: peak of xrd in SiC

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abstract: Contributors. Preface. Gallium Nitride (GaN) (V. Bougrov, et al. Aluminum Nitride (AIN) (Y. Goldberg) Indium Nitride (InN) (A. Zubrilov) Boron Nitride (BN) (S. Rumyantsev, et al. Silicon Carbide (SiC) (Y. Goldberg, et al. Silicon Germanium (Si 1 xGe x) (F. Schaffler) Appendix 1: Basic Physical Constants. Appendix 2: Periodic Table of the Elements. Appendix 3: Rectangular Coordinates for Hexagonal Crystal. Appendix 4: The First Brillouin Zone for Wurtzite Crystal. Appendix 5: Zinc Blende Structure. Appendix 6: The First Brillouin Zone for Zinc Blende Crystal. Additional References.
author_names: M E Levinshtein

Sergey Rumyantsev

Michael S Shur
title: Properties of advanced semiconductor materials GaN, AlN, InN, BN, SiC, SiGe
year: 2001

abstract: It has been recognized that Raman scattering spectroscopy is a powerful tool to characterize SiC crystals non destructively. We review recent significant developments in the use of Raman scattering to study structural and electronic properties of SiC crystals. The areas to be discussed in the first part include polytype identification, evaluation of stacking disorder and ion implantation damages, and stress evaluation. The Raman scattering by electronic transitions is discussed in the second part of this article. We concentrate on the plasmon LO phonon coupled modes whose spectral profiles are used to evaluate the carrier concentration and mobility. Anisotropic electronic properties of a SiC and characteristics of heavily doped crystals are discussed. Semiconductor to metal transition and Fano interference effect are also treated.
author_names: Shin-ichi Nakashima

Hiroshi Harima
title: Raman Investigation of SiC Polytypes
year: 1997

abstract: Fityk is portable, open source software for nonlinear curve fitting and data analysis. It specializes in fitting a sum of bell shaped functions to experimental data. In particular, it enables Pawley refinement of powder diffraction data and size strain analysis.
author_names: Marcin Wojdyr
title: Fityk: a general purpose peak fitting program
year: 2010

abstract: Abstract Neutron irradiation induced defects in 3C SiC irradiated to 2.8 4.2 x 10 26 n/m 2 at 480 735 degC were investigated by XRD measurement, isochronal annealing and DFT calculation. The XRD peak shift revealed different features between the specimens irradiated at 480 degC and higher temperature than 585 degC. The peak shifts were larger at the higher angle in the specimen irradiated at 480 degC, while the specimens irradiated at higher temperature than 585 degC, amounts of their peak shifts were not simply related to the diffraction angles. Crystal lattice of the specimen irradiated at 480 degC was considered to expand isotropically due to the irradiation. On the other hand, that of the specimens irradiated at higher temperature than 585 degC would expand anisotropically. Modification of XRD profile by the formation of various kinds of point defects and their clusters in 3C SiC was simulated using Rietveld method based on the DFT calculation results. Formation of the C C100 dumbbell complex defect expressed well the XRD peak shifts of 3C SiC irradiated above 585 degC.
author_names: Takashi Sawabe

Masafumi Akiyoshi

Katsumi Yoshida

Toyohiko Yano
title: Estimation of neutron irradiation induced defect in 3C SiC from change in XRD peak shift and DFT study
year: 2011

abstract: We uncover the constitutive relation of graphene and probe the physics of its optical phonons by studying its Raman spectrum as a function of uniaxial strain. We find that the doubly degenerate E(2g) optical mode splits in two components: one polarized along the strain and the other perpendicular. This splits the G peak into two bands, which we call G( and G( by analogy with the effect of curvature on the nanotube G peak. Both peaks redshift with increasing strain and their splitting increases, in excellent agreement with first principles calculations. Their relative intensities are found to depend on light polarization, which provides a useful tool to probe the graphene crystallographic orientation with respect to the strain. The 2D and 2D( bands also redshift but do not split for small strains. We study the Gruneisen parameters for the phonons responsible for the G, D, and D( peaks. These can be used to measure the amount of uniaxial or biaxial strain, providing a fundamental tool for nanoelectronics, where strain monitoring is of paramount importance.
author_names: T M G Mohiuddin

Antonio Lombardo

Rahul R Nair

Alessandro Bonetti

Gianluca Savini

Rashid Jalil

Nicola Bonini

Denis M Basko

Costas Galiotis

Nicola Marzari

Kostya S Novoselov

Andre K Geim

Andrea C Ferrari
title: Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
year: 2009

abstract: Abstract Hydroxyapatite (HA) nanoparticles were prepared by microwave synthesis method and the obtained powder is annealed at 800 degC for 2 h. The annealed HA particles were characterized by X ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy methods. The HA size and morphology were examined using a transmission electron microscope (TEM) The XRD results reveal that the diffraction peaks of the annealed HA were of well crystalline and correspond to the hexagonal crystal structure. The XRD and FTIR results confirm the absence of secondary phases such as b tricalcium phosphate (b TCP) and calcium oxide in annealed HA particles. The TEM result confirms the hexagonal structure of annealed HA and the particles were observed to be of ellipsoid like shaped morphology with less agglomeration. The lattice strain, crystallite size, lattice deformation stress and deformation energy density for annealed (800 degC) HA nanoparticles were estimated by Williamson Hall isotropic strain model W H ISM) W H anisotropic strain model W H ASM) and W H energy density model W H EDM) based on Williamson Hall W H plot from powder X ray diffraction data. The results of estimated average crystallite size of annealed HA by Scherrer and W H plot methods were compared with TEM results. It is found that the average crystallite size measured by W H plot methods is in good agreement with TEM results.
author_names: K Venkateswarlu

Arumugam Chandra Bose

N Rameshbabu
title: X ray peak broadening studies of nanocrystalline hydroxyapatite by Williamson Hall analysis
year: 2010

abstract: A strong substrate graphite bond is found in the first all carbon layer by density functional theory calculations and x ray diffraction for few graphene layers grown epitaxially on SiC. This first layer is devoid of graphene electronic properties and acts as a buffer layer. The graphene nature of the film is recovered by the second carbon layer grown on both the (0001) and (0001[over] 4H SiC surfaces. We also present evidence of a charge transfer that depends on the interface geometry. Hence the graphene is doped and a gap opens at the Dirac point after three Bernal stacked carbon layers are formed.
author_names: F Varchon

R Feng

Joanna Hass

Xiaofeng Li

B Ngoc Nguyen

Cecile Naud

Pierre Mallet

Jean Yves Veuillen

Claire Berger

Edward H Conrad

Laurence Magaud
title: Electronic structure of epitaxial graphene layers on SiC: effect of the substrate.
venue: Physical review letters
year: 2007

abstract: Abstract The XRD Omega method was used to determine the residual stress in a CVD diamond coating deposited on a SiC substrate. The (4 0 0) plane of CVD diamond was used with a tilt angle (ps) from 0 to 60 degrees. A compressive stress of 130 MPa with a standard deviation (SD) value of 28 MPa was obtained. Stress results obtained from the indentation method and Raman spectroscopy analysis were also compared with the XRD stress values. Indentation testing of the CVD diamond was performed using a microhardness tester with a Vickers diamond indenter under a load of 1 2.5 kgf. All stress values obtained correlated closely to results obtained by XRD. These results collectively illustrate that these coatings contain compressive stress associated with their deposition process.
author_names: S P Chowdhury

M T Laugier

John Henry
title: XRD stress analysis of CVD diamond coatings on SiC substrates
year: 2007

abstract: Abstract Preliminary XPS and XRD studies of the 3C SiC polycrystals (with the grain size of order of 100 mm) grown by the sublimation method were performed. The XRD data proved a dominant 3C SiC structure accompanied by an admixture of the residual 6H SiC phase. The main core level photoelectron spectra were analysed in detail. In particular, the C 1s level spectrum revealed a three peaks structure containing the peak indicative of free carbon as well as the remaining two identified as the carbidic components, centered at E B a =282.3 eV and E B b =283.4 eV. The fact, that the most intensive peak 'a' was found especially well resolvable in the acquired spectrum (as not observed in the earlier reports) was linked with a dominance of 3C SiC phase and a relatively high lattice perfection of the crystals studied. Therefore, it enabled us a reliable identification of the main C 1s line component (peak 'a' as related to the C Si bond in cubic Si 1 x C x crystal with slight deviation from stoichiometry (0.5 x 0.54) On the other hand, the minor carbidic component (peak 'b' was ascribed to the C Si bond in the highly C saturated cubic Si 1 x C x x 0.6) compound that is present in the surface region.
author_names: Ryszard J Iwanowski

Krzysztof Fronc

Wojciech Paszkowicz

Markku Heinonen
title: XPS and XRD study of crystalline 3C SiC grown by sublimation method
year: 1999

abstract: The crystal quality, stress and strain of GaN grown on 4H SiC and sapphire are characterized by high resolution X ray diffraction (HRXRD) and Raman spectroscopy. The large stress in GaN leads to the generation of a large number of dislocations. The Raman stress is determined by the results of HRXRD. The position and line shape of the A1 longitudinal optical (LO) phonon mode is used to determine the free carrier concentration and electron mobility in GaN. The differences between free carrier concentration and electron mobility in GaN grown on sapphire and 4H SiC are analyzed.
author_names: Duan Huantao

Gu Wen-Ping

Zhang Jincheng

Hao Yue

Chen Chi

Ni Jin-Yu

Xu Shengrui
title: Characterization of GaN grown on 4H SiC and sapphire by Raman spectroscopy and high resolution XRD
year: 2009