Relaxation behavior of glassy selenium

The dynamics of the glass transition of amorphous selenium was investigated by using differential scanning calorimeter. The heat capacity data were analyzed applying the phenomenological Tool-Narayanaswamy-Moynihan (TNM) model in order to describe the relaxation behavior of a-Se. The TNM parameters were evaluated by fitting the enthalpic cycles and also one isothermal experiment. Furthermore, peak-shift method and several other methods of evaluating the TNM parameters were applied to confirm the results of curve fitting. The results are compared with the other published enthalpy and viscosity data, volume and enthalpy relaxation are compared on account of our previous mercury dilatometry measurements. We found out that the pre-exponential factor A and the apparent activation energy Δh* of structural relaxation are similar for volume and enthalpy relaxation and Δh* is very close to the activation energy of viscous flow.