Structural investigations on an amorphous Se90Te10 alloy produced by mechanical alloying using EXAFS, cumulant expansion and RMC simulations.
J Phys Condens Matter
; 24(12): 125401, 2012 Mar 28.
Article
en En
| MEDLINE
| ID: mdl-22371432
ABSTRACT
We investigated an amorphous Se(90)Te(10) alloy produced by mechanical alloying using two different approaches. First, we used extended x-ray absorption fine structure (EXAFS) spectroscopy and the cumulant expansion method using the Einstein model for the temperature dependence of the cumulants to obtain the cumulants C(*)(1), C(*)(2), and C(*)(3). From these, we found information about the structure of the alloy as well as the thermal and structural disorder, anharmonicity of the effective interatomic pair potentials, thermal expansion of the Se-Se and Se-Te bonds and asymmetry of the partial distribution functions g(Se-Se)(r) and g(Se-Te)(r). The cumulants C(*)(1), C(*)(2), and C(*)(3) also allowed us to reconstruct the g(EXAFS)(ij)(r,T) functions from EXAFS. Then, we made reverse Monte Carlo (RMC) simulations using the total structure factor S(K) obtained from synchrotron x-ray diffraction and the EXAFS oscillations χ(k) on the Se K edge as input data to obtain the g(RMC)(ij)(r) functions. Both methods furnished very similar g(ij)(r) functions, and the structural data obtained from them were also very similar. The results obtained from both methods showed the presence of Se-Te pairs indicating that there is alloying at the atomic level. In addition, we could not find any evidence of the presence of Te clusters in the alloy.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Phys Condens Matter
Asunto de la revista:
BIOFISICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Brasil