High-Resolution X-Ray Diffraction Analysis of “Devicequality” Cubic GaN Grown on (001)GaAs Substrate Prepared by Atomic-Hydrogen Treatment At “High Temperatures”

1997 ◽  
Vol 482 ◽  
Author(s):  
A. Yoshikawa ◽  
Z. X. Qin ◽  
H. Nagano ◽  
Y. Sugure ◽  
A. W. Jia ◽  
...  
Keyword(s):  
High Resolution ◽  
High Temperatures ◽  
Atomic Hydrogen ◽  
Plasma Source ◽  
Hydrogen Treatment ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Cubic Gan ◽  
First Time

AbstractCubic GaN (c-GaN) layers were grown by if-plasma source MBE on (001) GaAs prepared by atomic-hydrogen treatment at “high temperatures”, and the structural properties of the epilayers were investigated by the high-resolution X-ray rocking curve and the reciprocal space mapping measurements. The growth temperature was varied from 620 to 740°C. It was found that single domain “device-quality” c-GaN layers could be grown for the first time; the FWHM of the X-ray rocking curves for the (002) c-GaN could be as small as 70 - 90 arcsec and the inclusion of h-GaN phase in the c-GaN epilayers grown at temperatures above 680°C could be less than 4×10-3.

Structure of fluorite-like compound based on Nd5Mo3O16with lead partly substituting for neodymium

2015 ◽  
Vol 71 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Alexander M. Antipin ◽  
Natalia I. Sorokina ◽  
Olga A. Alekseeva ◽  
Alexandra N. Kuskova ◽  
Elena P. Kharitonova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Single Crystal ◽  
Experimental Verification ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
X Ray ◽  
Oxygen Ion ◽  
First Time ◽  
Edx Microanalysis

A single crystal of Nd5Mo3O16with lead partly substituting for neodymium, which has a fluorite-like structure, was studied by precision X-ray diffraction, high-resolution transmission microscopy and EDX microanalysis. The crystal structure is determined in the space group Pn\bar 3n. It was found that the Pb atoms substitute in part for Nd atoms in the structure and are located in the vicinity of Nd2 positions. Partial substitutions of Mo cations for Nd positions and of Nd for Mo positions in crystals of theLn5Mo3O16oxide family are corroborated by X-ray diffraction for the first time. The first experimental verification of the location of an additional oxygen ion in the voids abutting MoO4tetrahedra was obtained.

Study on Cubic GaN Growth on (001) Rutile TiO2 Substrates by ECR-MBE

2002 ◽  
Vol 743 ◽  
Author(s):  
T. Araki ◽  
H. Mamiya ◽  
K. Kitamura ◽  
Y. Nanishi
Keyword(s):  
Electron Cyclotron Resonance ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
Preferential Growth ◽  
X Ray ◽  
Luminescence Peak ◽  
Cubic Gan ◽  
First Time ◽  
Preferential Growth Orientation ◽  
Resonance Plasma

ABSTRACTGaN layers were grown on a (001) rutile TiO2 substrate by electron cyclotron resonance plasma-excited molecular beam epitaxy. For the first time, c-GaN with a preferential growth orientation was obtained. Based on the results from electron diffraction and X-ray diffraction analysis, we found that c-GaN with the growth direction of [110] was grown on the TiO2 substrate. The formation of c-GaN was also confirmed by cathodoluminescence, in which a luminescence peak was observed at 3.24eV.

Experimental and Theoretical Study of the Triple-Crystal High-Resolution X-Ray Diffraction Scheme in Reciprocal Space Mapping Technique

2019 ◽  
Vol 64 (4) ◽  
pp. 545-552 ◽  
Author(s):  
A. Yu. Seregin ◽  
P. A. Prosekov ◽  
F. N. Chukhovsky ◽  
Yu. A. Volkovsky ◽  
A. E. Blagov ◽  
...  
Keyword(s):  
High Resolution ◽  
Theoretical Study ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Mapping Technique ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray

Comparative High-Resolution X-Ray Diffraction Analysis of GaN/AlGaN Heterostructure on Al2O3 and Si (111) Substrate Grown by Plasma Assisted Molecular Beam Epitaxy

2015 ◽  
Vol 1754 ◽  
pp. 129-134
Author(s):  
Sanjay Kr. Jana ◽  
Saptarsi Ghosh ◽  
Syed Mukulika Dinara ◽  
Apurba Chakraorty ◽  
D. Biswas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Field Emission ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Scanning Electron

AbstractThe work presents a comparative study on GaN/AlGaN type-II heterostructures grown on c-plane Al2O3 and Si (111) substrates by Plasma Assisted Molecular Beam Epitaxy. The in-depth structural characterizations of these samples were performed by High-Resolution X-Ray Diffraction, X-ray Reflectivity and Field Emission Scanning Electron Microscopy. The in-plane and out-of plane strains were determined from measured c- and a-lattice parameters of the epilayers from reciprocal space mapping of both symmetric triple axis (002) and asymmetric grazing incidence (105) double axis mode. The mosaicity parameters like tilt and correlation lengths were also calculated from reciprocal space mapping. Moreover, the twist angle was measured from skew symmetric off axis scan of (102), (103), and (105) planes along with (002) symmetric plane. The defect density were measured from the full width at half maxima of skew symmetric scan of (002) and (102) reflection planes. Also, the strained states of all the layers were analyzed and corresponding Al mole fraction was calculated based on anisotropic elastic theory. The thicknesses of the layers were measured from simulation of the nominal structure by fitting with X-ray Reflectivity experimental curves and also by comparing with cross sectional Field Emission Scanning Electron Microscopy micrographs.

scholarly journals Magnetically Separable Chiral Periodic Mesoporous Organosilica Nanoparticles

2020 ◽  
Vol 10 (17) ◽  
pp. 5960
Author(s):  
Suheir Omar ◽  
Raed Abu-Reziq
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Periodic Mesoporous Organosilica ◽  
X Ray ◽  
Mesoporous Organosilica ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
First Time

We describe, for the first time, a successful strategy for synthesizing chiral periodic mesoporous organosilica nanoparticles (PMO NPs). The chiral PMO nanoparticles were synthesized in a sol–gel process under mild conditions; their preparation was mediated by hydrolysis and condensation of chiral-bridged organo-alkoxysilane precursor compounds, (OR‘)3Si-R-Si(OR‘)3, in the presence of cetyltrimethylammonium bromide (CTAB) surfactant. The resulting nanoparticles were composed merely from a chiral- bridged organo-alkoxysilane monomer. These systems were prepared by applying different surfactants and ligands that finally afforded monodispersed chiral PMO NPs consisting of 100% bridged-organosilane precursor. In addition, the major advancement that was achieved here was, for the first time, success in preparing magnetic chiral PMO NPs. These nanoparticles were synthesized by the co-polymerization of 1,1′-((1R,2R)-1,2-diphenylethane-1,2-diyl)bis(3-(3-(triethoxysilyl) propyl) urea) chiral monomer by an oil in water (o/w) emulsion process, to afford magnetic chiral PMO NPs with magnetite NPs in their cores. The obtained materials were characterized with high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (XRD), solid-state NMR analysis, circular dichroism (CD) analysis, and nitrogen sorption analysis (N2-BET).

scholarly journals Thermal expansion in BaRuO3 perovskites – an unusual case of bond strengthening at high temperatures

2017 ◽  
Vol 46 (9) ◽  
pp. 2974-2980 ◽  
Author(s):  
Paula Kayser ◽  
Sean Injac ◽  
Brendan J. Kennedy ◽  
Andre L. Menezes de Oliveira ◽  
Yuichi Shirako ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Resolution ◽  
High Temperatures ◽  
Room Temperature ◽  
Unusual Case ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Dependences

The temperature dependences of the structures of three polytypes of BaRuO3 have been investigated between room temperature and 1000 °C using high resolution synchrotron X-ray diffraction.

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