Anharmonicity of thermal vibrations and Grüneisen parameter of chalcogenide glasses in the Ge-As-S system within the approximation of the free volume concept

• Published in: Glass physics and chemistry Vol. 26; no. 5; pp. 397 - 403
• Main Authors: MEL'NICHENKO, T. N, YURKIN, I. M, FEDELESH, V. I, MEL'NICHENKO, T. D
• Format: Journal Article
• Language: English
• Published: Moscow Kluwer/Plenum 01-09-2000; New York, NY Nauka/Interperiodica; Springer Nature B.V
• Subjects: Anharmonicity; Chalcogenides; Chemical bonds; Elongation; Glass; Gruneisen parameter
• ISSN: 1087-6596; 1608-313X
• DOI: 10.1007/BF02732057

The Grüneisen parameter and the ultimate strain of “bond breaking” at the ultimate elongation of interparticle bonds have been calculated. The Grüneisen parameters determined from different formulas are compared. It is demonstrated that the volume deformation required to form a microvoid in the glass network only slightly depends on glass composition. The microvoid volume is determined primarily by the ultimate strain of the interatomic bond. In chalcogenide glasses, the ultimate strain of the interatomic bond is governed by the limiting displacement of a bridging chalcogen atom, which varies in inverse proportion to the lattice Grüneisen parameter. The role of the Grüneisen parameter in the fluctuation free volume and soft configuration models is discussed.