X-ray and neutron diffraction studies and reverse Monte Carlo simulations of an amorphous Ni60Ti40 alloy produced by mechanical alloying

The local atomic order of an amorphous Ni60Ti40 alloy produced by mechanical alloying was studied by x-ray diffraction (XRD) and neutron diffraction techniques (ND). The total structure factors derived from the XRD and ND measurements were simulated by using the reverse Monte Carlo (RMC) method. The simulations were used to compute the partial pair distribution functions G(ij)(RMC) (r) and the partial structure factors S-ij(RMC) (K). From these functions, coordination numbers and interatomic distances for the first neighbours were calculated. There is a shortening in the heteropolar distance and a preference in forming unlike pairs, indicating a relatively strong chemical short-range order in the alloy.