Stress-driven crystallization of amorphous metal oxide film by glass transition in metallic glass

In the present study, we demonstrate that glass transition phenomenon in metallic glass can induce the crystallization of amorphous metal oxide film thermally grown on the metallic glass. In the case of the Ni₄₅Zr₃₅Ti₂₀ metallic glass, the amorphous metal oxide film is locally crystallized when a sudden change in the expansion coefficient of the substrate occurs by the glass transition. Interestingly, multiple crystal nuclei form simultaneously within the amorphous oxide film at fairly regular intervals. This suggests that the stress applied to the oxide film could be a major factor affecting the crystallization of the amorphous metal oxide film.