Electron microscopy of transformations produced in GeTe thin films by irradiation

Abstract

Amorphous thin films of two different Ge-Te alloys were prepared by simultaneous evaporation in vacuum. Morphological and structural transformations produced in the films by laser or electron beam irradiation were studied using transmission electron microscopy and selected area electron diffraction. As the irradiation power is increased minute microcrystals are segregated followed by crystallization of the whole irradiated spot, and finally a hole surrounded by a crystalline rim is formed. Digital information can be recorded on these Ge-Te films as bright or dark spots by using open holes or crystalline spots respectively. © 1985.