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The structure of near stoichiometric Ge-Ga-Sb-S glasses: A reverse Monte Carlo study

2018; Elsevier BV; Volume: 505; Linguagem: Inglês

10.1016/j.jnoncrysol.2018.11.009

1873-4812

Ildikó Pethes, V. Nazabal, Radwan Chahal, Bruno Bureau, I. Kaban, B. Beuneu, Jozef Bednarčík, P. Jóvári,

Crystal Structures and Properties

The structure of Ge22Ga3Sb10S65 and Ge15Ga10Sb10S65 glasses was investigated by neutron diffraction (ND), X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS) measurements at the Ge, Ga and Sb K-edges. Experimental data sets were fitted simultaneously in the framework of the reverse Monte Carlo (RMC) simulation technique. Short range order parameters were determined from the obtained large-scale configurations. It was found that the coordination numbers of Ge, Sb and S are around the values predicted by the Mott-rule (4, 3 and 2, respectively). The Ga atoms have on average 4 nearest neighbors. The structure of these stoichiometric glasses can be described by the chemically ordered network model: Ge-S, Ga-S and Sb-S bonds are the most important. Long Sb-S distances (0.3–0.4 Å higher than the usual covalent bond lengths) are observed, suggesting that Sb atoms can be found in various local environments.