Structural and thermal investigations of an amorphous GaSe{sub 9} alloy using EXAFS, cumulant expansion, and reverse Monte Carlo simulations

Journal Article · Sat Feb 07 04:00:00 EST 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4907280· OSTI ID:22416079

Siqueira, M. C.; Maia, R. N. A.; Araujo, R. M. T.; Stolf, S. F. ^[1]

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1. Centro de Engenharia e Ciências Exatas, UNIOESTE, 85903-000 Toledo, Paraná (Brazil)

In this article, we investigated structural and thermal properties of an amorphous alloy of the Ga–Se system. The amorphous GaSe{sub 9} alloy was produced by mechanical alloying and it was studied using EXAFS spectroscopy and cumulant expansion method. We also made reverse Monte Carlo simulations using the total structure factor S(K) obtained from x-ray diffraction and the EXAFS χ(k) oscillations on Se and Ga K edges as input data. Several parameters, such as average coordination numbers and interatomic distances, structural and thermal disorders, asymmetry of the partial distribution functions g{sub ij}(r), and Einstein and Debye temperatures, were determined. The g{sub ij}{sup E}(r) functions were reconstructed from the cumulants C{sub 1}, C{sub 2}, and C{sub 3} obtained from the Einstein model, and they were compared to the g{sub ij}{sup RMC}(r) functions obtained from the simulations. The simulations also furnished the partial bond angle distribution functions Θ{sub ijℓ}(cosθ), which describe the angular distribution of bonds between first neighbors, and give information about the kind of structural units present in the alloy.

• OSTI ID: 22416079
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 5 Vol. 142; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
AMORPHOUS STATE
ANGULAR DISTRIBUTION
BOND ANGLE
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DEBYE TEMPERATURE
DISTRIBUTION FUNCTIONS
FINE STRUCTURE
GALLIUM ALLOYS
GALLIUM SELENIDES
INTERATOMIC DISTANCES
MONTE CARLO METHOD
OSCILLATIONS
SELENIUM ALLOYS
STRUCTURE FACTORS
THERMODYNAMIC PROPERTIES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY