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

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.
Authors:
; ; ;  [1] ;  [2]
  1. Departamento de Física, Centro Politécnico, Universidade Federal do Paraná, 81531-990 Curitiba, Paraná (Brazil)
  2. Centro de Engenharia e Ciências Exatas, UNIOESTE, 85903-000 Toledo, Paraná (Brazil)
Publication Date:
OSTI Identifier:
22416079
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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