Pressure induced atomic packing evolution and crystallization in La₇₅Al₂₅ metallic glass

The pressure-induced structural transformation in metallic glass (MG) is a challenging and important subject in condensed matter physics. In the present first-principles molecular dynamics study, the atomic packing of La₇₅Al₂₅ MG under pressure was investigated, and the structure was predicted to crystallize at 92 GPa. It is found that the distributions of La and Al atoms are not homogeneous, as often assumed. In particular, Al atoms form aggregates in the glass structure, exhibiting strong covalent characteristics of the Al–Al bonds. The pressure-induced crystallization is not only caused by the dominant packing of the larger La atoms but is also facilitated by the presence of these rigid Al clusters.