Layer polymorphous crystallizations of amorphous films: structural and kinetic aspects

Abstract

Structural and geometric aspects of layer polymorphic crystallization of thin amorphous films were considered. The review of electron microscopic studies of crystallization “in situ” of amorphous films under the influence of the electron beam was provided. Digital video recording in real time t of structural and phase changes occurring in the film was applied. Kinetic crystallization curves were constructed and the parameters reflecting the growth of crystals of various morphologies in amorphous film were defined. Electron-beam crystallization of amorphous films is accompanied by the formation of Cr2O3 and V2O3 crystals of three basic morphological forms: disk-shaped, sickle-shaped and needle-shaped, the kinetics of growth of which is different. The growth of disk-shaped crystals occurs at a constant rate; the degree of crystallinity x ∼ t 2, and the rate of change in the fraction of the crystalline phase x't ∼ t. Sickle-shaped (at the initial stage) crystal, as it grows, changes its morphology in the sequence: sickle-shaped → ring-shaped → disk-shaped crystal.