KINEMATICAL TRANSFORMATIONS OF AMORPHOUS SELENIUM BY DTA MEASUREMENT

The effect of sample preparation procedures on the glass transition and crystallization of amorphous Se has been studied by differential thermal analysis. The glass transition mechanism is essentially identical in the amorphous Se samples prepared by meltquenching and vapour deposition. In contrast, melt-quenched amorphous Se exhibits a double-step crystallization process, as revealed by an asymmetric DTA peak with a shoulder, while there appears a narrow single peak in the crystallization exothermic curve of vapour-deposited Se. These characteristics in the kinematical transformation of amorphous Se samples are discussed using a disordered chain model in which a statistical occupation of Se atoms at the cis- and trans-site in a molecule is proposed. © 1979 Chapman and Hall Ltd.