Anharmonicity of thermal vibrations and grueneisen 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, VI, Mel'nichenko, T D
• Format: Journal Article
• Language: English
• Published: 01-09-2000
• Subjects: Bonding; Chalcogenides; Chemical bonds; Glass; Mathematical models; Networks; Strain; Vibration
• ISSN: 1087-6596; 1608-313X
• DOI: 10.1007/BF02732057

The Grueneisen parameter and the ultimate strain of "bond breaking" at the ultimate elongation of interparticle bonds have been calculated. The Grueneisen 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 Grueneisen parameter. The role of the Grueneisen parameter in the fluctuation free volume and soft configuration models is discussed.