Mechanisms of fast crystallization in amorphous Ge₂Sb₂Te₅ films

Abstract

Ge2Sb2Te5 has been widely utilized as phase-change films, while a long-standing problem is the seemingly paradoxical feature; room-temperature durability of amorphous states which undergo rapid crystallization upon pulsed, optical/electrical excitations. The model that takes high fragility of the film into account has been proposed for reconciling this contrastive behavior, while the idea faces some difficulties. This work suggests through simple calculations that explosive latent-heat spikes produced by ns pulses could accelerate the crystallization. Although crystal growths are assumed to need some durations, the latent heat generated by shorter stimuli is able to trigger the swift crystallization.