The glassy state of the semiconducting system Ge10SbxSe90-x

The glass-transition temperature (T-g) has been determined for the system Ge10SbxSe90-x with x = 5, 10, 15, 20 and 25 using differential thermal analysis (DTA) at a heating rate phi = 5, 10, 15 and 20 degrees C/min. The effect of the heating rate and the Sb content on T-g is discussed. Using differential scanning calorimetry (DSC), the relation between the Sb content and the heat absorbed in the endothermic peak (Delta H J/kg) corresponding to the glass transition at 5 degrees C/min, the differences in heat capacity (Delta C-p) and specific heat (Delta c(p)) have been obtained. The DC conductivity for each composition has been determined in the temperature range 309-442 K. The glass-transition temperature and the energy gaps (E-g) for the solid and the soft glassy states have been obtained. Both increase with increasing Sb content or average coordination number. An empirical equation has been deduced which relates the glass-transition temperature with the Sb content. (C) 2000 Elsevier Science B.V. All rights reserved.