Characterization Of Si-Doped GaN on (00.1) Sapphire Grown by MOCVD

1997 ◽  
Vol 482 ◽  
Author(s):  
Chang Soo Kim ◽  
Dong-Kun Lee ◽  
Cheul-Ro Lee ◽  
Sam Kyu Now ◽  
In-Hwan Lee ◽  
...  
Keyword(s):  
Hall Mobility ◽  
Strain Relaxation ◽  
Mapping Technique ◽  
Yellow Luminescence ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
Peak Intensity Ratio ◽  
Si Doped ◽  
Good Agreement

AbstractWe investigated structural, electrical and optical properties and their relationships for MOCVD grown Si-doped GaN with different doping levels. The changes in structural properties such as strain, crystallinity and strain relaxation as a function of carrier concentrations were measured by high-resolution triple-axis X-ray diffraction and reciprocal space mapping technique. As the carrier concentration of the samples increases from 1.6×1018 to 9.5×1018/cm3 Hall mobility decreases from 222 to 170cm2/Vsec, and peak intensity ratio of band edge to yellow luminescence in photoluminescence spectra decreases too. The variation of mosaic spread along [00.1] direction determined from full width at half maximum(FWHM) of GaN (00.2) peaks shows good agreement with the variation in Hall mobility. In addition, dislocation density determined from FWHM of (10.2) peaks is shown to be related to the variation in the intensity of yellow luminescence in PL spectra.

3-Dimensional Characterization of Polycrystalline Bulk Materials Using High-Energy Synchrotron Radiation

2007 ◽  
Vol 539-543 ◽  
pp. 2353-2358 ◽  
Author(s):  
Ulrich Lienert ◽  
Jonathan Almer ◽  
Bo Jakobsen ◽  
Wolfgang Pantleon ◽  
Henning Friis Poulsen ◽  
...  
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
High Energy ◽  
Mapping Technique ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
Reciprocal Space Mapping ◽  
3 Dimensional ◽  
Individual Grains

The implementation of 3-Dimensional X-Ray Diffraction (3DXRD) Microscopy at the Advanced Photon Source is described. The technique enables the non-destructive structural characterization of polycrystalline bulk materials and is therefore suitable for in situ studies during thermo-mechanical processing. High energy synchrotron radiation and area detectors are employed. First, a forward modeling approach for the reconstruction of grain boundaries from high resolution diffraction images is described. Second, a high resolution reciprocal space mapping technique of individual grains is presented.

Effect of C and Ge Concentration On The Thermal Stability of RTCVD Grown Si1-x-yGexCy Alloys

1997 ◽  
Vol 470 ◽  
Author(s):  
Patricia Warren ◽  
Stephane Retzmanick ◽  
Martin Gotza ◽  
Marc Begems
Keyword(s):  
Lattice Constant ◽  
Strain Relaxation ◽  
Mechanical Strain ◽  
Chemical Vapor ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Cubic Silicon Carbide ◽  
Kinetics Of ◽  
Good Agreement

ABSTRACTSi / Si1-x-yGexCy / Si heterostructures containing up to 17 at.% Ge and 1.9 at.% C were grown on (001) silicon by low pressure Rapid Thermal Chemical Vapor Deposition, using a mixture of silane, germane and methylsilane, diluted in hydrogen. The samples were then annealed in a Rapid Thermal Processing furnace, under an atmospheric pressure of nitrogen, at temperatures ranging from 900 to 1130 °C.The samples were characterized using infrared spectroscopy and x-ray diffraction. SIMS profiling and TEM observation were performed on some of the samples.Substitutional C gradually disappeared, either precipitating out to form cubic silicon carbide (β-SiC), or simply vanishing into interstitial positions. In any case, the in-plane lattice constant remained constant after annealing, indicating that there was no mechanical strain relaxation by formation of misfit dislocations. The perpendicular lattice constant increased due to the decrease in substitutional C concentration, as well as it decreased due to the germanium out-diffusion. This variation of the strain during annealing was modeled, and allowed the determination of the kinetics of the substitutional carbon disappearance. The same behavior was observed for all samples. Indeed, the Cs disappearance rate was always increased for samples with higher initial Ge and C concentrations. The kinetics of this precipitation was found in very good agreement with previous published results.

Characterization of Strain Relaxation Process during Ge Condensation by Synchrotron Microbeam X-ray Diffraction

2008 ◽  
Author(s):  
T. Inoue ◽  
D. Shimokawa ◽  
T. Hosoi ◽  
T. Shimura ◽  
Y. Imai ◽  
...  
Keyword(s):  
Relaxation Process ◽  
Strain Relaxation ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Preparation of Zirconium Oxide Powder Using Zirconium Carboxylate Precursors

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed H. Al-Hazmi ◽  
YongMan Choi ◽  
Allen W. Apblett
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Dissociative Adsorption ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Experimental Findings ◽  
Periodic Dft Calculations ◽  
Good Agreement

Zirconia was prepared at low temperatures (<450°C) using single several source precursors based on zirconium carboxylates where the R groups were systematically varied. The combination of density functional theory (DFT) calculations and extensive characterization of the precursors (i.e., X-ray diffraction, thermal gravimetric analysis, infrared spectroscopy, and scanning electron microscopy) indicated that the carboxylic acid complexes may link the zirconium metal with a cis bidentate configuration. Periodic DFT calculations were performed to examine the interaction between monoclinic ZrO2 and propanoic acid. Dissociative adsorption takes place through the cis bidentate structure with an adsorption energy of −1.43 eV. Calculated vibrational frequencies using the optimized structure are in good agreement with experimental findings.

Asymmetrical reciprocal space mapping using X-ray diffraction: a technique for structural characterization of GaN/AlN superlattices

CrystEngComm ◽  
2017 ◽  
Vol 19 (22) ◽  
pp. 2977-2982 ◽  
Author(s):  
H. V. Stanchu ◽  
A. V. Kuchuk ◽  
M. Barchuk ◽  
Yu. I. Mazur ◽  
V. P. Kladko ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Space Mapping ◽  
Reciprocal Space ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray

Synthesis and Characterization of Fe3O4 Nanoparticles Stabilized by Polyvinylpyrrolidone/Polyethylene Glycol with Variable Mass Ratios

2016 ◽  
Vol 869 ◽  
pp. 880-883
Author(s):  
Fernanda A. Sampaio da Silva ◽  
Marcos Flavio de Campos ◽  
Edwin E.G. Rojas
Keyword(s):  
Polyethylene Glycol ◽  
Variable Mass ◽  
Rietveld Analysis ◽  
Polymer Mixture ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Cancer Treatments ◽  
Varying Mass ◽  
Good Agreement

Magnetic nanoparticles are devices able to optimize cancer treatments. In particular, magnetite nanoparticles are very effective in producing heat to cause lysis of tumor cells. However, in order that nanoparticles are internalized without causing damage to body they must be coated by biocompatible material. In this work, Fe3O4 nanoparticles were coated by a polymer blend: polyethylene glycol / polyvinylpyrrolidone. Some variations in mass ratio of polymer mixture were made. The effect of varying mass ratio in polymers was investigated. Samples were characterized by X-ray diffraction and Rietveld analysis. Moreover, hysteresis curves were analyzed. The results indicate good agreement between mass proportions used and physical and magnetic properties of nanocomposite.

Structural Studies Of Epitaxial CdF2 Layers on Si(111)

1996 ◽  
Vol 441 ◽  
Author(s):  
A. Yu. Khilko ◽  
R. N. Kyutt ◽  
G. N. Mosina ◽  
N. S. Sokolov ◽  
Yu. V. Shusterman ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Optimal Growth ◽  
Misfit Strain ◽  
X Ray Diffraction ◽  
Optimal Growth Temperature ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Transmission Electron

AbstractEpitaxial CdF2 layers, which may be used in light-emitting devices integrated with silicon, were grown by Molecular Beam Epitaxy (MBE). Characterization of the layers by Rutherford Backscattering Spectroscopy (RBS), X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) showed that optimal growth temperature lies in the range 60–80°C. The sticking coefficient of CdF2 molecules was found to decrease at temperatures above 100°C. Different modes of misfit strain relaxation were observed above and below that temperature.

scholarly journals Structural Characterization of Heteroepitaxial Growth of AlxGa1-xSb/GaSb by LPE

2014 ◽  
Vol 70 (a1) ◽  
pp. C1795-C1795
Author(s):  
Primavera Lopez ◽  
Javier Martinez ◽  
Gabriel Juarez ◽  
Joel Diaz
Keyword(s):  
Liquid Phase ◽  
Aluminum Content ◽  
Reciprocal Space ◽  
Diffraction Maximum ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Crystallographic Tilt

The heteroepitaxial AlxGa1-xSb/GaSb (001) growth with different x aluminum content, from 0.05 to 0.2 prepared by Liquid Phase Epitaxy (LPE) is presented. The interest in this study is due to the layers of AlxGa1-xSb systems should be well matched for fabrication of sources and detectors operating in the 1.3-1.6 micron range. The layered structure obtained was characterized mainly by high-resolution X-ray diffraction and reciprocal space mapping. In the case of x = 0.05 aluminum content, the relaxation is minimal, and almost without deviation respect to GaSb. As the aluminum content increases above 0.05, the relaxation is larger and deviation from GaSb substrate too. Crystallographic tilt is detected by a shift of layer diffraction maximum on reciprocal space maps. Deviation changes the intensity of layer respect to substrate peak in rocking curves and hence the estimation of thickness of layer obtained from them. A correction for estimated thickness of layers is obtained from mapping.

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