InN Nano Rods and Epitaxial Layers Grown by HVPE on Sapphire Substrates and GaN, AlGaN, AlN Templates

2005 ◽  
Vol 892 ◽  
Author(s):  
Alexander Syrkin ◽  
Alexander Usikov ◽  
Vitali Soukhoveev ◽  
Oleg Kovalenkov ◽  
Vladimir Ivantsov ◽  
...  

AbstractThis paper contains results on InN growth by Hydride Vapor Phase Epitaxy (HVPE) on various substrates including sapphire, GaN/sapphire, AlGaN/sapphire, and AlN/sapphire templates. The growth processes were carried out at atmospheric pressure in a hot wall reactor in the temperature range from 500 to 650°C. Arrays of nano-crystalline InN rods with various shapes were grown directly on sapphire substrates. Continuous InN layers were grown on GaN/sapphire, AlN/sapphire and AlGaN/sapphire template substrates. X-ray diffraction rocking curves for the (00.2) InN reflection exhibit the full width at half maximum (FWHM) as narrow as 0.075 deg. for the nano-rods and 0.128 deg. for the continuous layers grown on GaN/sapphire templates.

1995 ◽  
Vol 401 ◽  
Author(s):  
Yoshihiko Shibata ◽  
Naohiro Kuze ◽  
Masahiro Matsui ◽  
Masaki Kanal ◽  
Tomoji Kawai

AbstractThin LINbO3 films are deposited on (001) sapphire and (001) LiTaO3 substrates by using pulsed excimer-laser ablation. These films are evaluated by high-resolution X-ray diffraction (HRXRD) analysis. Strained LiNbO3 films in which the a-axis is longer and the c-axis is shorter than those of LiNbO3 single crystals are deposited on the sapphire substrates. On the other hand, extremely high-quality LiNbO3 films in which the a-axis of the films is the same as that of substrates are grown on the LiTaO substrates. X-ray rocking curves for the (006) reflection showed very narrow full width at half maximum (FWHM) of 208 arcsec for the films on the sapphire substrates, and 9 arcsec for the films on LiTaO3 substrates.


Author(s):  
В.Н. Бессолов ◽  
М.Е. Компан ◽  
Е.В. Коненкова ◽  
В.Н. Пантелеев

A new approach is proposed to the synthesis of a semipolar AlN on a Si(100) substrate at the surface for which the angle between the inclined plane of the nanogrooves and Si(100) is 47°. It is shown that the hydride vapor-phase epitaxy on a such nano-patterned substrate enables formation of a semipolar layer AlN (1012) characterized by the full width at half maximum value as low as ωθ ~60 arcmin for the x-ray diffraction rocking curve. It is found that the Raman spectra of the semipolar AlN(10-12) layer contain additional peaks on the Raman curves associated with phonons A1(TO) and E1(TO), in contrast to the polar AlN(0001) layer, where the peak A1(LO) is additionally manifested.


1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.


2015 ◽  
Vol 34 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Victor F. Tarasenko ◽  
Igor' D. Kostyrya ◽  
Dmitry V. Beloplotov

AbstractIn the paper, we study the conditions for the generation of backward runaway electrons through a grounded grid cathode in atmospheric pressure air at high-voltage pulses with a full width at half maximum of 1 ns and risetime of 0.3 ns applied to the gap from a SLEP-150 pulser. The study confirms that backward runaway electrons and X-rays do arise near grid cathodes in atmospheric pressure air. It is shown that the current of the backward beam and the X-rays from the gas diode depend differently on the interelectrode distance. The average X-ray exposure dose in a pulse is more than 3.5 mR.


2018 ◽  
Vol 941 ◽  
pp. 2093-2098
Author(s):  
Naho Itagaki ◽  
Kazuto Takeuchi ◽  
Nanoka Miyahara ◽  
Kouki Imoto ◽  
Hyun Woong Seo ◽  
...  

We studied effects of sputtering pressure on growth of (ZnO)x(InN)1-xcrystal films deposited at 450°C by rf magnetron sputtering. Epitaxial growth of (ZnO)x(InN)1-xfilms was realized on single-crystalline ZnO template. X-ray diffraction measurements show that full width at half maximum of the rocking curves from the (101) plane of the films reaches minimum value of 0.11º at 0.5 Pa. The sputtering gas pressure is a key tuning knob for controlling the crystal quality of ZION films.


Clay Minerals ◽  
2001 ◽  
Vol 36 (2) ◽  
pp. 143-157 ◽  
Author(s):  
B. Kübler ◽  
D. Goy-Eggenberger

AbstractThe main reason for the initial determinations of illite crystallinity (IC) was to support the exploration for liquid and gaseous hydrocarbons. The application in 1960 of the Weaver Sharpness Ratio to core materials of a borehole from eastern France indicated that it was not a reliable tool for identifying well-crystallized illite. This ratio was later replaced by the Full Width at Half-Maximum (FWHM), the value of which decreases regularly and consistently towards greenschist facies. The use of FWHM allowed a precise definition of the anchimetamorphic zone between the upper diagenesis and the epimetamorphism. Afterwards, analysis of weak-tointermediate diagenetic sequences showed that illite crystallinity decreases together with the amount of swelling interlayers in mixed-layer clay minerals. Technological improvements, such as computing and modelling of X-ray diffraction patterns, increased the analytical precision relative to measurements of the plain FWHM. Consequently, illite crystallinity went back to its initial use, namely detection of the transitions between diagenesis, anchi- and epi-metamorphism in smectitefree lithologies, where it can be used as a stratigraphic and mineralogic marker of alteration stages.


2008 ◽  
Vol 388 ◽  
pp. 7-10 ◽  
Author(s):  
Masayuki Takada ◽  
Shinzo Yoshikado

The effects of the thermally annealing of Bi-Mn-Co-Sb2O3-added ZnO varistors on their electrical degradation were investigated. For the samples with 0.01mol% Sb2O3added and without Sb2O3, no marked difference in the non linearity index of the voltage-current (V-I) characteristics was observed upon electrical degradation for the annealed and nonannealed samples. Upon increasing the amount of Sb2O3 added, the values of  increased after electrical degradation for the annealed samples. Moreover, the value of  after electrical degradation was proportional to the full width at half maximum (FWHM) of the X-ray diffraction peak for Zn2.33Sb0.67O4-type spinel particles under various annealing conditions. The added Sb2O3 did not dissolve in the ZnO grains but became segregated at grain boundaries. Therefore, it is speculated that the increase in the FWHM for the spinel particles is due to the increase in the numbers of fine spinel particles at grain boundaries and triple points.


2009 ◽  
Vol 2009 (0) ◽  
pp. 654-655
Author(s):  
Takayoshi SUZUKI ◽  
Jun-ichi SHIBANO ◽  
Koji KIRIYAMA ◽  
Takayuki ARAI ◽  
Setsuo MIURA ◽  
...  

1999 ◽  
Vol 55 (5) ◽  
pp. 840-854 ◽  
Author(s):  
Gunnar Thorkildsen ◽  
Helge B. Larsen

A general formalism, based on the Takagi–Taupin equations, for calculating rocking curves in perfect t\times l crystals is presented. It includes nonsymmetrical scattering, refraction, and ordinary and anomalous absorption. t and l may be varied independently. In the limit of a semi-infinite crystal, the standard results from the fundamental theory are retrieved. For crystal dimensions less than the extinction length, the theory converges to the kinematical limit. Simulations for germanium and silicon show significant influence of crystal finiteness. When dynamical effects are prominent, the curves exhibit various degrees of asymmetry and the full width at half-maximum is generally larger than the corresponding Darwin width. This is attributed to combined Laue and Bragg contributions which are shifted with respect to each other owing to refraction.


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