Thermal Properties of Amorphous Selenium over the Glass- Transition Range

Authors: Mukhtar Veliev ISMAIL

Abstract: In has been shown that the heat capacity (C_{p}), coefficients of heat conductivity, (\lambda) and thermal expansion, (\alpha), for the amorphous selenium are dependent on the temperature of the transition from glass-forming state into a high elasticity condition. On this transition these quantities are increased by AC_{p}=3,47 kal/deg\cdotmol, \Delta\ \lambda=0,32\cdot 10^{-3} cal/sec\cdot deg., \delta\alpha=0,79\cdot 10^{-5} deg^{-1}. These increments are due to the contribution by the increased concentration of holes. Contribution of holes in the glass-forming region was calculated using the formulae by Hirai and Eyring for 1 mol of \lq\lq heads", which is equal to C_{p}=3,06 kal/deg\cdotmol. The \lq\lq hole" theory for liquids is used as a strating point in the calculation of the \lambda and \alpha. The obtained resuls are: \lambda =0,28\cdot 10^{-3} kal/cm\cdotsec\cdotdeg. \alpha=0,73\cdot 10^{-5} deg^{-1}. These quantities for C_{p}, \lambda and \alpha are in satisfactory agreement with experimental data.

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