Annealing-induced amorphization in a sputtered glass-forming film: In-situ transmission electron microscopy observation

The annealing-induced amorphization of a sputtered glass-forming Cu51Zr42Al4Ti3 thin film has been clarified by in-situ transmission electron microscopy in conjunction with ex-situ atomic force microscopy and X-ray diffractometry. Upon heating of the film at low temperatures, nanocrystallization and growth of metastable sputtered crystallites occur in the amorphous matrix. Heated to 438 °C, within the supercooled liquid region (ΔT), the film becomes fully amorphous. At higher temperatures above ΔT, i.e. 525 °C, crystalline Cu10Zr7 and AlTi2 phases appear as a result of crystallization. The annealing-induced nanocrystallization and amorphization appear to be rather general and applicable to a large number of systems.