Local atomic arrangements of pd-based bulk metallic glasses of the metal-metalloid type demonstrated by molecular dynamics simulations

Molecular dynamics (MD) simulations based on a plastic crystal model (PCM) were performed for a Pd_0.4Ni_0.4P_0.2 alloy in Metal-Metalloid (M-MLD) type of bulk metallic glass (BMG). Two kinds of clusters of cubeoctahedron capped with four half-octahedra and trigonal prism were used as initial atomic arrangements of the Pd_0.4Ni_0.4P _0.2 alloy. Random rotations of clusters around their centers of gravity and subsequent structural relaxation vitrified the alloy. The high glass-forming ability of the Pd_0.4Ni_0.4P_0.2 alloy is due to the critically-percolated, cluster-packed structure that is a universal feature for both M-MLD and M-M types of BMGs.