Heat Capacity and Structural Relaxation of Enthalpy in As ₂ Se ₃ Glass

Abstract

The evolution of enthalpy of As 2 Se 3 glass during structural relaxation in the glass transition region was measured via differential scanning calorimetry for two types of time‐temperature programs: rate‐heating at 10 K/min following a cool at a constant rate (‐20 to ‐0.31 K/min) and isothermal annealing following a temperature step from an equilibrium state. The rate‐heating data yield kinetic parameters for the structural relaxation which predict accurately the evolution of the enthalpy during isothermal annealing. The glass heat capacities were independent of cooling rate within experimental precision (≤0.2%). In this respect, As 2 Se 3 is unlike previously studied glasses whose heat capacities are more dependent on thermal history.