scholarly journals X Ray Diffraction: An Approach to Structural Quality of Biological Preserved Tissues in Tissue Banks

10.5772/33725 ◽  
2012 ◽  
Author(s):  
H. Perez ◽  
Mc. Saldias ◽  
G. Sanchez ◽  
P. Martucci ◽  
Mc. Acosta ◽  
...  
Keyword(s):  
Structural Quality ◽  
Tissue Banks ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Исследование этапов превращения кремния в карбид кремния в процессе атомного замещения методами полного внешнего отражения рентгеновских лучей и рентгеновской дифрактомерии

2022 ◽  
Vol 64 (3) ◽  
pp. 326
Author(s):  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
Е.В. Осипова ◽  
В.М. Стожаров
Keyword(s):  
Structural Quality ◽  
Total External Reflection ◽  
X Rays ◽  
Reflection Method ◽  
X Ray Diffraction ◽  
Modified Technique ◽  
Substitution Method ◽  
X Ray ◽  
Sic Films

X-ray diffraction and total external reflection of X-rays (X-ray reflectometry) methods were used to study the successive stages of synthesis of epitaxial SiC films on Si (100) X-ray diffraction and total external X-ray reflection (XRD) methods were used to study successive stages of synthesis of epitaxial SiC films on Si (100) surfaces, (110) and (111) surfaces by the atom substitution method. The data on the transformation evolution of (100) surfaces were studied, (110) and (111) Si, into SiC surfaces. A comparative analysis of the X-ray structural quality of the SiC layers grown on Si by the atom substitution method with the quality of SiC layers grown by Advanced Epi by the standard CVD method. A modified technique for the total outer X-ray reflection method, based on measurements of the intensity of the reflected X-rays using a special parabolic mirror. It is shown that the method of total external reflection method makes it possible to obtain important information about the degree of surface roughness of SiC layers, the evolution of their crystal structure and plasmon energy in the process of Si to SiC conversion.

Study of the structural quality of heteroepitaxial silicon-on-sapphire structures by high-resolution X-ray diffraction, X-ray reflectivity, and electron microscopy

2014 ◽  
Vol 59 (3) ◽  
pp. 315-322 ◽  
Author(s):  
A. E. Blagov ◽  
A. L. Vasiliev ◽  
A. S. Golubeva ◽  
I. A. Ivanov ◽  
O. A. Kondratev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray

INFLUENCE OF Al MONOLAYERS ON THE PROPERTIES OF AlN LAYERS ON Si (111)

2009 ◽  
Vol 16 (01) ◽  
pp. 99-103 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
H. ABU HASSAN
Keyword(s):  
Buffer Layers ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Surfaces ◽  
Gan On Si ◽  
Aln Buffer ◽  
Xrd Techniques ◽  
Substrate Temperatures

High-quality aluminum nitride ( AlN ) layers with full width at half maximum (FWHM) values of 11 arcmin were grown by plasma-assisted molecular-beam epitaxy on Si (111) substrates. AlN nucleation layers are being investigated for the growth of GaN on Si . Growth using AlN buffer layers leads to Al -polar films, with surfaces strongly dependent on the flux conditions used. Flat surfaces can be obtained by growing as Al -rich as possible, although Al droplets tend to form. Before starting the AlN growth, a few monolayers of Al are deposited on the substrate to avoid the formation of Si 3 N 4. X-ray diffraction (XRD) techniques were employed to determine the surface and structural quality of the layers. XRD revealed that monocrystalline AlN was obtained. Best AlN films were obtained at high substrate temperatures (875°C) and III/V ratios close to stoichiometry.

High Resolution X-ray Diffraction of GaN Grown on Sapphire Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
A. Saxler ◽  
M. A. Capano ◽  
W. C. Mitchel ◽  
P. Kung ◽  
X. Zhang ◽  
...  
Keyword(s):  
Metalorganic Chemical Vapor Deposition ◽  
Reciprocal Lattice ◽  
Chemical Vapor ◽  
Lattice Points ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Primary Mechanism

ABSTRACTX-ray rocking curves are frequently used to assess the structural quality of GaN thin films. In order to understand the information given by the line shape, we need to know the primary mechanism by which the curves are broadened. The GaN films used in this study were grown by low pressure metalorganic chemical vapor deposition (MOCVD) on (00•1) sapphire substrates. GaN films with both broad and very narrow (open detector linewidth of 40 arcseconds for the (00•2) GaN reflection) rocking curves are examined in this work. Reciprocal space maps of both symmetric and asymmetric reciprocal lattice points are used to determine that the cause of the broadening of GaN rocking curves is a limited in-plane coherence length.

scholarly journals Optical and structural studies of Hg0.7Cd0.3Te samples grown by various methods

2021 ◽  
Vol 2103 (1) ◽  
pp. 012148
Author(s):  
D A Andryushchenko ◽  
M S Ruzhevich ◽  
A M Smirnov ◽  
N L Bazhenov ◽  
K D Mynbaev
Keyword(s):  
Molar Fraction ◽  
Optoelectronic Devices ◽  
Considerable Degree ◽  
Structural Quality ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Disorder ◽  
Photoluminescence Studies

Abstract Photoluminescence and X-ray diffraction (XRD) were used for the studies of the properties of HgCdTe samples with CdTe molar fraction x=0.3 grown by various methods. According to the results of photoluminescence studies, all samples possessed a considerable degree of alloy disorder, yet the scale of the disorder seemed not to be directly related to the structural quality of the material as revealed using XRD. Prospects of using HgCdTe material grown by various methods in optoelectronic devices are discussed.

High Epitaxial Growth Rate of 4H-SiC Using Horizontal Hot-Wall CVD

2006 ◽  
Vol 527-529 ◽  
pp. 187-190 ◽  
Author(s):  
Rachael L. Myers-Ward ◽  
Y. Shishkin ◽  
Olof Kordina ◽  
I. Haselbarth ◽  
Stephen E. Saddow
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Growth Process ◽  
Structural Quality ◽  
Growth Time ◽  
Film Morphology ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray

A 4H-SiC epitaxial growth process has been developed in a horizontal hot-wall CVD reactor using a standard chemistry of silane-propane-hydrogen, producing repeatable growth rates up to 32 μm/h. The growth rate was studied as a function of pressure, silane flow rate, and growth time. The structural quality of the films was determined by X-ray diffraction. A 65 μm thick epitaxial layer was grown at the 32 μm/h rate, resulting in a smooth, specular film morphology with occasional carrot-like and triangular defects. The film proved to be of high structural quality with an X-ray rocking curve FWHM value of the (0004) peak of 11 arcseconds.

Superconducting Multilayers: Microstructural Properties Studied by X-Ray Diffraction

1995 ◽  
Vol 382 ◽  
Author(s):  
A. Vailionis ◽  
A. Brazdeikis ◽  
A.S. FlodstrÖm
Keyword(s):  
Molecular Beam ◽  
Interface Roughness ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
One Dimensional ◽  
X Ray ◽  
Structural Imperfections ◽  
Cell Disorder

ABSTRACTStructural properties of molecular beam epitaxy-grown Bi2Sr2Cu1Oy'Bi2Sr2Ca1Cu2Oy multilayers have been studied by x-ray diffraction. A one-dimensional kinematic x-ray diffraction model has been used to describe the structural quality of the multilayers. Interface roughness, stacking defects and unit cell disorder are obtained by an iterative fitting of the calculated diffraction profile to the experimental spectra. The type and amount of disorder in the films was qualitatively determined. Results demonstrate that structural imperfections are present in the multilayers and have to be considered when transport properties are studied.

HVPE Growth of GaN Layers on Cleaved β-Ga2O3 Substrates

2016 ◽  
Vol 674 ◽  
pp. 302-307 ◽  
Author(s):  
V.I. Nikolaev ◽  
A.I. Pechnikov ◽  
S.I. Stepanov ◽  
V.M. Krymov ◽  
V.N. Maslov ◽  
...  
Keyword(s):  
Deposition Time ◽  
Substrate Surface ◽  
Vapour Phase ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Nucleation Layer ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Gan Film

GaN epitaxial layers were successfully grown by hydride vapour phase epitaxy (HVPE) on β-Ga2O3 substrates produced by cleaving. The initial stages of GaN epitaxial growth on β-Ga2O3 were studied by scanning electron microscopy (SEM) and x-ray diffraction analysis (XRD). The nucleation and the transition from the nucleation layer to a continuous GaN film were studied. It was found that the growth starts with formation of small crystallites on the substrate surface. As the growth continues, crystallites transform into pyramidal islands which increase in size and merge together. It was found that the structural quality of the GaN layers rapidly improves with increasing thickness. The full width at half maximum of x-ray ω rocking curves for (0002) peak decreased from 1370 to 540 arcsec as the deposition time was increased from 30 to 120 sec. This corresponds to the variation of the nominal layer thickness from 250 nm to 1000 nm.

scholarly journals Оптические и структурные свойства эпитаксиальных слоев Hg-=SUB=-0.7-=/SUB=-Cd-=SUB=-0.3-=/SUB=-Te

2021 ◽  
Vol 55 (11) ◽  
pp. 1040
Author(s):  
Д.А. Андрющенко ◽  
М.С. Ружевич ◽  
А.М. Смирнов ◽  
Н.Л. Баженов ◽  
К.Д. Мынбаев ◽  
...  
Keyword(s):  
Solid Solution ◽  
Optical Properties ◽  
Diffraction Data ◽  
Epitaxial Films ◽  
Structural Quality ◽  
Bulk Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photoluminescence Studies

The results of comparative studies of the optical and structural properties of Hg0.7Cd0.3Te bulk crystals and epitaxial films grown by various methods are presented. The data of photoluminescence studies performed in the temperature range 4.2−300K showed the similarity of the optical properties of different samples and indicated a significant disordering of the solid solution. According to X-ray diffraction data, however, the scale of the disordering was not directly related to the structural quality of the material. The prospects for using the material grown by various methods in optoelectronics applications are discussed.

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