Study of lattice deformation and atomic bond length for AlxGa1−xN epi-layers with synchrotron radiation X-ray absorption spectroscopy

2014 ◽  
Vol 25 (11) ◽  
pp. 4800-4805
Author(s):  
Shuchang Wang ◽  
Xiong Zhang ◽  
Muchi Liu ◽  
Bowei Wang ◽  
Zhe Chuan Feng ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Bond Length ◽  
Absorption Spectroscopy ◽  
Lattice Deformation ◽  
X Ray ◽  
X Ray Absorption

X-ray absorption spectroscopy and tunable color emission study of the Mn-co-doped BaAl2O4: Ce phosphor under synchrotron radiation

2019 ◽  
Vol 91 ◽  
pp. 401-407 ◽  
Author(s):  
Simone S. Melo ◽  
Adriano B. Andrade ◽  
Giordano F.C. Bispo ◽  
Jessica C. Carvalho ◽  
Zélia S. Macedo ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Spectroscopy ◽  
X Ray ◽  
Emission Study ◽  
X Ray Absorption ◽  
Co Doped ◽  
Color Emission

Oxidation State of Ti Atoms and Ti-O Bond Length on Natural Sapphire Gem-Materials Probed by X-Ray Absorption Spectroscopy

2017 ◽  
Vol 737 ◽  
pp. 585-589 ◽  
Author(s):  
Natthapong Monarumit ◽  
Wiwat Wongkokua ◽  
Somruedee Satitkune
Keyword(s):  
Bond Length ◽  
Oxidation State ◽  
Absorption Spectroscopy ◽  
Germanium Detector ◽  
Blue Color ◽  
Edge Structure ◽  
X Ray ◽  
Fe Content ◽  
X Ray Absorption ◽  
Exafs Spectra

Sapphire, an inorganic gem-material in a variety of corundum, mainly consists of alpha-alumina (α-Al2O3) structure. The geological origins of sapphire are related to either basaltic or metamorphic rocks. The causes of the color on sapphire are some trace elements such as Cr, Fe, and Ti. It could be mentioned that Ti atoms have cooperated with Fe atoms for creating the blue color. In this study, X-ray absorption spectroscopy (XAS) technique focused on the x-ray absorption near edge structure (XANES) and the extended x-ray absorption fine structure (EXAFS) is employed to identify the oxidation state of Ti atoms and Ti-O bond length on sapphire samples. The Ti K-edge XANES and EXAFS spectra of natural sapphires were carried out using the 13-channel array germanium detector in fluorescence mode. The XANES spectra showed that the oxidation state of Ti was Ti4+ regardless of Fe content. Moreover, the Ti-O bond length on a-Al2O3 was equal to the Ti-O bond length on rutile (TiO2) analyzed from the EXAFS spectra. From these results, it could be concluded that the oxidation state of Ti atoms on natural sapphires was Ti4+ which substitutes Al3+ on the sapphire structure.

scholarly journals Synchrotron Radiation X-Ray Absorption Spectroscopy and Spectroscopic Ellipsometry Studies of InSb Thin Films on GaAs Grown by Metalorganic Chemical Vapor Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yingda Qian ◽  
Yuanlan Liang ◽  
Xuguang Luo ◽  
Kaiyan He ◽  
Wenhong Sun ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Synchrotron Radiation ◽  
Absorption Spectroscopy ◽  
Spectroscopic Ellipsometry ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray ◽  
X Ray Absorption ◽  
Metalorganic Chemical

A series of ultrathin InSb films grown on GaAs by low-pressure metalorganic chemical vapor deposition with different V/III ratios were investigated thoroughly using spectroscopic ellipsometry (SE), X-ray diffraction, and synchrotron radiation X-ray absorption spectroscopy. The results predicted that InSb films on GaAs grown under too high or too low V/III ratios are with poor quality, while those grown with proper V/III ratios of 4.20–4.78 possess the high crystalline quality. The temperature-dependent SE (20–300°C) and simulation showed smooth variations of SE spectra, optical constants (n, k, e1, and ε2), and critical energy points (E1, E1+Δ1, E′0, E2, and E′1) for InSb film when temperature increased from 20°C to 250°C, while at 300°C, large changes appeared. Our study revealed the oxidation of about two atomic layers and the formation of an indium-oxide (InO) layer of ∼5.4 nm. This indicates the high temperature limitation for the use of InSb/GaAs materials, up to 250°C.

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