High Quality Hydrothermal ZnO Crystals

1998 ◽  
Vol 537 ◽  
Author(s):  
M. Suscavage ◽  
M. Harris ◽  
D. Bliss ◽  
P. Yip ◽  
S.-Q. Wang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Liquid Helium ◽  
Room Temperature ◽  
Surface Preparation ◽  
Critical Factor ◽  
High Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Oxide Crystals

AbstractZinc Oxide crystals have historically been grown in hydrothermal autoclaves with a basic mineralizer; however, doubts have been raised about the quality of such crystals because they have often exhibited large x-ray rocking curve widths and low photoluminescence (PL) yield with large linewidths. Several ZnO crystals were grown hydrothermally and sliced parallel to the c-plane. This resulted in opposite surfaces (the C+ and C-) exhibiting pronounced chemical and mechanical differences. Different surface treatments were investigated and compared by PL both at room temperature and liquid helium temperatures, and by double axis X-ray rocking curve measurements. The high quality of hydrothermally-grown ZnO is substantiated by the narrow rocking curve widths and sharp PL peaks obtained. A critical factor in obtaining these results was found to be surface preparation.

scholarly journals High Quality Hydrothermal ZnO Crystals

1999 ◽  
Vol 4 (S1) ◽  
pp. 287-292 ◽  
Author(s):  
M. Suscavage ◽  
M. Harris ◽  
D. Bliss ◽  
P. Yip ◽  
S.-Q. Wang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Liquid Helium ◽  
Room Temperature ◽  
Surface Preparation ◽  
Critical Factor ◽  
High Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Oxide Crystals

Zinc Oxide crystals have historically been grown in hydrothermal autoclaves with a basic mineralizer; however, doubts have been raised about the quality of such crystals because they have often exhibited large x-ray rocking curve widths and low photoluminescence (PL) yield with large linewidths. Several ZnO crystals were grown hydrothermally and sliced parallel to the c-plane. This resulted in opposite surfaces (the C+ and C−) exhibiting pronounced chemical and mechanical differences. Different surface treatments were investigated and compared by PL both at room temperature and liquid helium temperatures, and by double axis X-ray rocking curve measurements. The high quality of hydrothermally-grown ZnO is substantiated by the narrow rocking curve widths and sharp PL peaks obtained. A critical factor in obtaining these results was found to be surface preparation.

Growth of CuInGaSe2 Films by RF Sputtering Using CuInGaSe2 Single Phase Target

2013 ◽  
Vol 372 ◽  
pp. 571-574
Author(s):  
Kenji Yoshino ◽  
Takahiro Tokuda ◽  
Akira Nagaoka ◽  
Kenichiro Miseki ◽  
Rie Mori ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Rf Sputtering ◽  
Diffraction Peak ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
High Quality ◽  
Homogeneous Surface ◽  
X Ray

CuIn0.8Ga0.2Se2 thin film is grown at room temperature by RF sputtering using high quality of CuIn0.8Ga0.2Se2 single phase target. A (112) diffraction peak is dominant with no secondary phases such as selenide materials in the X-ray diffraction pattern. A flat and homogeneous surface can be obtained in the sample.

The Effect of Low Temperature GaAs Nucleation on the Growth of GaN on Silicon (001) During MOVPE Process

1997 ◽  
Vol 482 ◽  
Author(s):  
L. X. Zheng ◽  
J. W. Liang ◽  
H. Yang ◽  
J. B. Li ◽  
Y. T. Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
High Quality ◽  
Nucleation Layer ◽  
X Ray ◽  
Cubic Gan ◽  
Low Temperature Gaas

AbstractHigh quality cubic GaN was grown on Silicon (001) by metalorganic vapor phase epitaxy (MOVPE) using a GaAs nucleation layer grown at low temperature. The influence of various nucleation conditions on the GaN epilayers' quality was investigated. We found that the GaAs nucleation layer grown by atomic layer epitaxy (ALE) could improve the quality of GaN films by depressing the formation of mixed phase. Photoluminescence (PL) and X-ray diffraction were used to characterize the properties of GaN epilayers. High quality GaN epilayers with PL full width at half maximum (FWHM) of 130meV at room temperature and X-ray FWHM of 70 arc-min were obtained by using 10–20nm GaAs nucleation layer grown by ALE.

Successful protein cryocooling for powder diffraction

2007 ◽  
Vol 40 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Mark J. Jenner ◽  
Jonathan P. Wright ◽  
Irene Margiolaki ◽  
Andrew N. Fitch
Keyword(s):  
Powder Diffraction ◽  
Room Temperature ◽  
Egg White ◽  
Powder Diffraction Data ◽  
High Quality ◽  
X Ray ◽  
Egg White Lysozyme ◽  
Diffraction Peaks ◽  
Better Than

It is shown that samples of microcrystalline tetragonal chicken egg white lysozyme can be effectively cryoprotected for high-resolution synchrotron X-ray powder diffraction studies at 100 K. The survival of the powder in the beam is increased by a factor of around 30. Thus, a high-quality powder diffraction pattern could be collected at 100 K, which attains a resolution ofdmin≃ 2.6 Å, significantly better than the previous limit of ∼3.27 Å at room temperature, despite a smaller volume of sample. Systematic variations of the concentration and type of cryoprotectant agent show that the lattice microstrains that accompany cooling, and degrade the quality of the powder diffraction data by broadening the diffraction peaks, are caused by a collapse in the volume of the crystalline unit cell.

scholarly journals Lateral Growth of InN on GaN/Sapphire

2001 ◽  
Vol 693 ◽  
Author(s):  
Fuh-Hsiang Yang ◽  
Jih-Hsien Hwang ◽  
Kuei-Hsien Chen ◽  
Ying-Jay Yang
Keyword(s):  
Raman Spectrum ◽  
Surface Morphology ◽  
Growth Conditions ◽  
Epitaxial Films ◽  
Lateral Growth ◽  
High Quality ◽  
Stripe Pattern ◽  
Rocking Curve ◽  
X Ray

AbstractThe lateral growth of high quality InN on the stripe-pattern GaN/sapphire substrate with an OMVPE system was studied. The surface morphology and structural properties were investigated. Epitaxial films were achieved due to the greatly reduced strain by lateral growth. Two kinds of growth mode were observed due to different growth conditions of V/III ratios. X-ray rocking curve with FWHM of 700 arcsec shows the good quality of the film and E2 mode of Raman spectrum with FWHM of 3.5 cm-1 is among the best results ever reported in the literature.

A Study of the Interactions Between Oligoamidephosphate (OAPh) and Curatives in a Sulphenamide-Accelerated Sulphur Vulcanizing System

1999 ◽  
Vol 19 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Todorka G. Vladkova ◽  
Alexander Chr. Alaminov ◽  
Milka G. Pankova
Keyword(s):  
Differential Scanning Calorimetry ◽  
Zinc Oxide ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sulphur Vulcanization

Abstract The possible interactions between oligoamidephosphate (OAPli) and the curatives of a sulphenamide-accelerated sulphur vulcanizing system were studied by differential scanning calorimetry, IR-spectroscopy, and X-ray analysis. The interactions in double mixtures were between OAPh and zinc oxide (ZnO) and OAPh and sulphur. The OAPh/ZnO interaction that starts at room temperature seems to be the key for understanding the peculiarities of sulphenamide-accelerated sulphur vulcanization in the presence of OAPh.

scholarly journals Short-pulse laser-driven x-ray radiography

2016 ◽  
Vol 4 ◽  
Author(s):  
E. Brambrink ◽  
S. Baton ◽  
M. Koenig ◽  
R. Yurchak ◽  
N. Bidaut ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Short Pulse ◽  
Incident Angle ◽  
Laboratory Astrophysics ◽  
Signal To Noise ◽  
High Quality ◽  
X Ray ◽  
Short Pulse Laser ◽  
Short Pulse Lasers

We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths. Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.

Fabrication of Ultrathin Bragg Beam Splitter by Plasma Chemical Vaporization Machining

2012 ◽  
Vol 523-524 ◽  
pp. 40-45 ◽  
Author(s):  
Taito Osaka ◽  
Makina Yabashi ◽  
Yasuhisa Sano ◽  
Kensuke Tono ◽  
Yuichi Inubushi ◽  
...  
Keyword(s):  
Beam Splitter ◽  
Bragg Reflection ◽  
Free Electron Lasers ◽  
Crystalline Perfection ◽  
Plasma Chemical ◽  
High Quality ◽  
Rocking Curve ◽  
Mechanical Process ◽  
X Ray ◽  
Beam Splitters

A novel fabrication process was proposed to produce high-quality Bragg beam splitters for hard X-ray free-electron lasers (XFELs), which should consist of thin, bend-free, and robust Bragg-case crystals without any defects. A combination of a mechanical process and plasma chemical vaporization machining was employed. High crystalline perfection of the fabricated Si(110) crystal was verified with X-ray topography and rocking curve measurements. In addition, the thickness was evaluated to be 4.4 μm from the fringe period of the measured rocking curve. The crystal can be employed in Bragg beam splitters using the (220) Bragg reflection for X-ray pump-X-ray probe experiments with XFEL sources.

Electric and thermoelectric properties of CdTe/PbTe epitaxial nanocomposite

2014 ◽  
Vol 07 (06) ◽  
pp. 1440007
Author(s):  
Michal Szot ◽  
Krzysztof Dybko ◽  
Piotr Dziawa ◽  
Leszek Kowalczyk ◽  
Viktor Domukhovski ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Molecular Beam ◽  
High Quality ◽  
Polycrystalline Solid ◽  
Hall Effect Measurements ◽  
Shubnikov De Haas Oscillations

The electric and thermoelectric properties of novel, CdTe / PbTe layered nanocomposite material are investigated. The molecular beam epitaxy (MBE) method was used for preparation of samples with well controlled distances (from 20 to 70 nm) between the layers of CdTe nanograins embedded in PbTe thermoelectric matrix as well as with number of these layers from 2 to 10. The Hall effect measurements performed in temperature range from 4–300 K revealed that carrier mobility is strongly affected by scattering on CdTe grain boundaries. The observation of Shubnikov-de Haas oscillations confirms high quality of the samples and allows determination of effective mass of conducting electrons m* = 0.04m0. The measurements of the room temperature Seebeck coefficient together with electrical conductivity lead to the power factors which are comparable to those reported in PbTe / CdTe polycrystalline solid solutions.

scholarly journals Cubic InGaN Grown by MOCVD

1999 ◽  
Vol 4 (S1) ◽  
pp. 239-243
Author(s):  
J.B. Li ◽  
Hui Yang ◽  
L.X. Zheng ◽  
D.P. Xu ◽  
Y.T. Wang
Keyword(s):  
Room Temperature ◽  
Emission Peak ◽  
Buffer Layers ◽  
Cubic Phase ◽  
Yellow Luminescence ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cubic Gan ◽  
Pl Emission

We report on the growth of high-quality cubic phase InGaN on GaAs by MOCVD. The cubic InGaN layers are grown on cubic GaN buffer layers on GaAs (001) substrates. The surface morphology of the films are mirror-like. The cubic nature of the InGaN films is obtained by X-ray diffraction (XRD) measurements. The InGaN layers show strong photoluminescence (PL) at room temperature. Neither emission peak from wurtzite GaN nor yellow luminescence is observed in our films. The highest In content as determined by XRD is about 17% with an PL emission wavelength of 450 nm. The FWHM of the cubic InGaN PL peak are 153 meV and 216 meV for 427 nm and 450 nm emissions, respectively. It is found that the In compositions determined from XRD are not in agreement with those estimated from PL measurements. The reasons for this disagreement are discussed.

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