"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

Low-temperature specific heat and thermal conductivity of ternary chalcogenide glasses

E. VATEVA1,* , B. TERZIYSKA1, D. ARSOVA1

Affiliation

  1. Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria

Abstract

The main results from the investigated in the temperature range 3 - 300 K thermal properties, specific heat Cp and thermal conductivity k, of the GexAs40-xS60 glasses are reviewed and concurrently analyzed. The nonmonotonic dependences of the parameters of the universal low-temperature features on the composition (defined by the average coordination number Z) are correlated with their degree of the thermodynamic fragility. The correlation is based on the prevalence of the excess of vibrational soft modes (SM) in the less fragile glasses. Some assumptions of the soft-potential model (SPM) are checked and new Z dependences have been found for the energetic parameter connected with the delocalization of the SM. This parameter is calculated in two ways: according to relations obtained in the SPM, using an evaluated characteristic energy W, or using only the macroscopic material parameters of the studied glasses. A relation between the crossover temperature for the soft-mode delocalization and the temperature dependence of the calculated thermal diffusivity D is found. The complete analysis of the thermal characteristics leads to new scaling laws and new insight into some implications of the SPM clarifying the peculiarities of the peak in the Cp/T3 vs T plot and the plateau of k(T)..

Keywords

Chalcogenide glasses, Low-temperature thermal properties, Ge-As-S, Thermal conductivity.

Submitted at: May 30, 2007
Accepted at: July 15, 2007

Citation

E. VATEVA, B. TERZIYSKA, D. ARSOVA, Low-temperature specific heat and thermal conductivity of ternary chalcogenide glasses, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 7, pp. 1965-1973 (2007)