Investigation of multicomponent chemical short-range order in NiZr ₂

The local atomic configuration of multicomponent chemical short-range order (MCSRO) in NiZr₂ has been investigated by means of molecular dynamics simulation (MD) in a wide temperature range. The potential functions for the system based on the embedded atom method are constructed and the parameters are obtained by fitting the structure and properties of NiZr ₂ crystal. The static structures such as pair distribution functions and the distribution of coordination number have been calculated. The local atomic configurations of the MCSROs in the melt were demonstrated as distorted coordination polyhedron of the compound structure and/or the structure similar to cubooctahedron analogues. It is indicated by the results of MD simulation that above the melting point the atomic packing of long-range order disappears, but the chemical interaction of coordinated atoms still exists, which leads to the formation of various MCSROs with atomic configurations similar to the stable or metastable unit cell of NiZr₂ compound. When the system is just melted, many icosahedral polyhedron configurations appear, which decrease as the over-heating temperature increases.