Microsecond Carrier Lifetimes in Bulk-Like 3C-SiC Grown by Sublimation Epitaxy

2013 ◽  
Vol 740-742 ◽  
pp. 315-318
Author(s):  
Jian Wu Sun ◽  
Satoshi Kamiyama ◽  
Peter J. Wellmann ◽  
Rickard Liljedahl ◽  
R. Yakimova ◽  
...  
Keyword(s):  
High Resolution ◽  
Carrier Lifetime ◽  
Crystal Quality ◽  
Injection Level ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay

High quality bulk-like 3C-SiC were grown on on-axis (0001) 6H-SiC substrate by sublimation epitaxy. The microwave photoconductivity decay mapping measurements revealed that this material shows considerable long carrier lifetimes varied from 3.519 to 7.834 μs under the injection level of 3.5×1012 cm-2, which are comparable with the best carrier lifetimes in 4H-SiC layers. The mapping of high resolution x-ray diffraction obtained from the same region shows that smaller carrier lifetimes seem to correspond to the larger FWHM values and vice versa. This shows that long carrier lifetime obtained in 3C-SiC is due to the improvement of the crystal quality.

scholarly journals Experimental Investigations of the Interaction of SO2 with MgO

1999 ◽  
Vol 590 ◽  
Author(s):  
Andrea Freitag ◽  
J. A. Rodriguez ◽  
J. Z. Larese
Keyword(s):  
High Resolution ◽  
Film Thickness ◽  
Room Temperature ◽  
Temperature Programmed Desorption ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Temperature Programmed ◽  
X Ray Absorption

ABSTRACTHigh resolution adsorption isotherms, temperature programmed desorption (TPD), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES) methods were used to investigate the interaction of SO2 with high quality MgO powders. The results of these investigations indicate that when SO2 is deposited on MgO in monolayer quantities at temperatures near 100K both SO3 and SO4 species form that are not removed by simply pumping on the pre-dosed samples at room temperature. TPD and XANES studies indicate that heating of pre-dosed MgO samples to temperatures above 350 °C is required for full removal of the SO3/SO4 species. XANES measurements made as a function of film thickness indicate for coverages near monolayer completion that the SO4 species form first.

scholarly journals Measuring Curved Crystal Performance for a High-Resolution, Imaging X-Ray Spectrometer

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Michael J. Haugh ◽  
Richard Stewart
Keyword(s):  
High Resolution ◽  
Resolving Power ◽  
Inertial Confinement ◽  
High Resolution Imaging ◽  
Doppler Broadening ◽  
X Ray Diffraction ◽  
High Quality ◽  
Reflectivity Curve ◽  
X Ray ◽  
Resolution Imaging

This paper describes the design, crystal selection, and crystal testing for a vertical Johann spectrometer operating in the 13 keV range to measure ion Doppler broadening in inertial confinement plasmas. The spectrometer is designed to use thin, curved, mica crystals to achieve a resolving power of E/ΔE>2000. A number of natural mica crystals were screened for flatness and X-ray diffraction width to find samples of sufficient perfection for use in the instrument. Procedures to select and mount high quality mica samples are discussed. A diode-type X-ray source coupled to a dual goniometer arrangement was used to measure the crystal reflectivity curve. A procedure was developed for evaluating the goniometer performance using a set of diffraction grade Si crystals. This goniometer system was invaluable for identifying the best original crystals for further use and developing the techniques to select satisfactory curved crystals for the spectrometer.

High Resolution X-Ray Diffraction Analysis of Piezoelectric LiNbO3 Films.

1995 ◽  
Vol 401 ◽  
Author(s):  
Yoshihiko Shibata ◽  
Naohiro Kuze ◽  
Masahiro Matsui ◽  
Masaki Kanal ◽  
Tomoji Kawai
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Sapphire Substrates

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.

scholarly journals Protein crystal quality studies using high resolution X-ray diffraction

2005 ◽  
Vol 61 (a1) ◽  
pp. c178-c178
Author(s):  
A. Meents ◽  
B. Reime ◽  
H. Schulz-Ritter ◽  
D. Elefant ◽  
R. Harf ◽  
...  
Keyword(s):  
High Resolution ◽  
Crystal Quality ◽  
Protein Crystal ◽  
X Ray Diffraction ◽  
X Ray

X-Ray Diffraction Analysis of Heteroepitaxial Cd1-yZnyTe on GaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
S. M. Johnson ◽  
W. L. Ahlgren ◽  
M. T. Smith ◽  
B. C. Johnston ◽  
S. Sen
Keyword(s):  
Plastic Deformation ◽  
High Resolution ◽  
Epitaxial Growth ◽  
Vapor Phase ◽  
Gaas Substrate ◽  
Lattice Mismatch ◽  
Tilt Boundary ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray

ABSTRACTX-ray diffraction techniques were used to evaluate Cd1-yZnyTe grown on GaAs substrate orientations of {100}2°, {111}, {012}, and {123}. High-quality layers having compositions at or close to the CdTe and ZnTe binary end points can be grown on GaAs, but most of the ternary compositions have extremely broad rocking curves. Layers grown on {123} and {012} were found to have large tilts toward {111} about <121> that varied systematically with the lattice mismatch; this is consistent with the mismatch being accommodated by the formation of a low-angle tilt boundary at the interface. {111} layers were found to be twinned, and thus {100}2° and {123} appear to better suited for vapor-phase epitaxial growth (VPE). High-resolution x-ray diffractometer measurements showed that the lattice mismatch is almost entirely taken up by plastic deformation, and only a small tetragonal distortion was measured. CdTe was distorted more than ZnTe, and a greater distortion was measured for layers grown on {100}2° than on {111}, in agreement with estimates made using bulk elastic constants.

A quality comparison of protein crystals grown under containerless conditions generated by diamagnetic levitation, silicone oil and agarose gel

2013 ◽  
Vol 69 (10) ◽  
pp. 1901-1910 ◽  
Author(s):  
Hui-Ling Cao ◽  
Li-Hua Sun ◽  
Jian Li ◽  
Lin Tang ◽  
Hui-Meng Lu ◽  
...  
Keyword(s):  
Silicone Oil ◽  
Crystal Quality ◽  
Protein Crystals ◽  
Agarose Gel ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Diamagnetic Levitation ◽  
High Quality Protein

High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and theRmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.

High Quality GaP Growth on Si Substrates By Mocvd

1988 ◽  
Vol 116 ◽  
Author(s):  
K. Uchida ◽  
Y. Kohama ◽  
M. Tajima ◽  
T. Soga ◽  
T. Jimbo ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
Diffraction Peak ◽  
Crystal Quality ◽  
X Ray Diffraction ◽  
High Quality ◽  
Double Crystal ◽  
X Ray ◽  
Si Substrates ◽  
Secondary Ion

AbstractGaP crystals are grown on Si substrates by MOCVD. Double crystal X-ray diffraction indicates that the crystal quality of GaP layers greatly improves when AsH3 is supplied before growth. The FWHM of (400) diffraction peak of the GaP layer decreases as the thickness increases and the best FWHM of 112.5 arcs is obtained at a thickness of 5 μm. The GaP/Si interface is characterized using secondary ion mass spectroscopy (SIMS) to demonstrate the effect of AsH3.

High resolution X-ray diffraction of MOVPE-grown ZnO/GaN/sapphire layers

2004 ◽  
Vol 219 (4) ◽  
Author(s):  
Steffi Deiter ◽  
Helvi Witek ◽  
Nikolay Oleynik ◽  
Jürgen Bläsing ◽  
Armin Dadgar ◽  
...  
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Vapor Phase ◽  
Growth Temperature ◽  
Growth Parameters ◽  
Metalorganic Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Wide Gap

AbstractHigh quality ZnO is an interesting material for electronic and optoelectronic applications. It belongs to the wide gap semiconductors (bandgap = 3.3 eV). In this paper we present ZnO layers grown by MOVPE (metalorganic vapor phase epitaxy). Several growth parameters like growth temperature and thickness of the layer were varied. For comprehensive investigations of the crystalline quality we employed different X-ray fine structure methods.

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