In situ AFM and Raman spectroscopy study of the crystallization behavior of Ge2Sb2Te5 films at different temperature

► The structure and morphology of Ge2Sb2Te5 film cooled to RT was different with that at high temperature. ► The structure of amorphous Ge2Sb2Te5 films began to change at a temperature of as low as 100 °C. ► The coverage of film surface with crystal and the morphology varied at different temperature. ► The crystallization process of Ge2Sb2Te5 film at different temperature is illustrated.