Polymeric nature of selenium crystallization. II. Crystallization kinetics and secondary crystallization

Abstract The crystallization of elemental selenium has been studied in light of present concepts of crystallization in organic polymers. Bulk‐crystallization kinetic data as measured by a dynamic density technique and spherulite growth‐rate data as measured by optical microscopy are presented for the temperature range 70°C to 160°C. Plots of extent of isothermal crystallization versus time were sigmoidal in shape. Spherulite growth rates were constant for a given temperature and reached a maximum at approximately 130°C. Evidence is presented for secondary crystallization in selenium, and a model is proposed for destruction of chain folds with interlamellar crystallization during the spherulitic‐to‐“metallic” transformation above 100°C.