Structural Relaxation in Amorphous Selenium Films Below the Glass Transition Temperature

The variation in the glass transition temperature of amorphous Se films, studied by means of differential thermal analysis, depends on the preparation conditions, and on the age of the samples and the temperature at which they are maintained. A thermodynamic brium is proposed. This model uses a relaxation time tau which is brium is proposed. This model uses a relaxation time tau which is a function of the temperature and the departure of the enthalpy from equilibrium: tau = aexp(--bT)exp --c(H--Hc) . The fitting of this model with experimental results permits the determination of the constants a and b, and then the dependence of the equilibrium relaxation time tau c = a exp(--bT) on temperature. The last result is in good agreement with those of Stephens (J. Appl. Phys., 1978, 49, 5855) which were determined by other methods. 11 ref.--AA