Microstructural analysis of simulated liquid and amorphous Ni

Molecular dynamics simulations and a systematic analysis of the local atomic structure have been done to investigate the microstructure of liquid and amorphous Ni. The n-body Gupta potential, based on the second moment approximation of a tight-binding Hamiltonian, was used to model the metallic bonding of the system. The calculated pair distribution function (PDF) of liquid and amorphous Ni are in agreement with experimental measurements. A decomposition of the first and second peaks of the PDF into components according to the local environment of the pairs shows that the atomic coordination of the liquid phase contains a high abundance of icosahedral and distorted icosahedral structures. Crystalline and icosahedral (regular and distorted) atomic configurations contribute in approximately the same proportion to the short-range order of the amorphous phase. These results indicate that n-body interactions favor the formation of crystalline order in amorphous metals.