Large-scale atomistic study of plasticity in amorphous gallium oxide with ab-initio accuracy

Abstract

Compared to the widely investigated crystalline polymorphs of gallium oxide (), knowledge about its amorphous state is very limited. With the help of a machine-learning interatomic potential, we conducted large-scale atomistic simulations to investigate the formation and plastic behavior of amorphous (a-). Amorphization of gallium oxide melt is successfully observed at ultrahigh cooling rates, including a distinct glass transition. The glass transition temperature is evaluated to range from 1234 to 1348 K at different cooling rates. Structural analysis shows similarities between a- and amorphous alumina (a-) in many aspects, including pair distribution function, coordination distribution, and bond angle distribution. In the tension simulations, highly plastic behavior at room temperature is observed, highly comparable to a-. Based on multiple quantitative characterization results, we show that a- exhibits a higher nucleation rate of localized plastic strain events compared to a-, which can increase the material’s resistance to shear banding formation during deformation.