Pressure dependent evolution of microstructures in Pd80Si20 bulk metallic glass

Abstract

The effect of the pressure on the local microstructure in the amorphous Pd80Si20 alloy was investigated by coordination analyses and structural calculations using molecular dynamics simulations. We observed that the glass transition temperature increases monotonically as the pressure increases. Also, it was seen that the Pd atoms composing the face centered cubic (fcc)- and icosahedral-like order are the origin of the complexity of the local structure while the short-range order around Si atoms is characterized by a tri-capped trigonal prism. We found that the topological structure and local environment of the system which consists of icosahedral-, hexagonal- and fcc-like structural units, change significantly with the effect of pressure. We revealed that the short-range order of the system develops with pressure due to the increase of icosahedral and some defected icosahedral polyhedra, and Pd atoms are responsible for the formation of the amorphous state of the system.