Modeling the atomic structure of an amorphous NiZr(3) alloy by anomalous wide angle x-ray scattering and reverse Monte Carlo simulation.

The amorphous atomic structure of a melt-spun NiZr(3) alloy was investigated using the anomalous wide angle x-ray scattering (AWAXS) and reverse Monte Carlo (RMC) simulation techniques. The AWAXS data were collected at four incident photon energies, including ones close to the Ni and Zr K-edges, and four total structure factors S(K) were derived. Differential structure factors DAS(K) around the Ni and Zr atoms were calculated through the difference between the scattered intensities on a per-atom scale obtained at incident photon energy pairs (8330, 9455 eV) and (15622, 17993 eV). The contribution of the partial S(Ni-Ni)(K) for the Ni-DAS(K) factor is six times bigger than the one for the S(K) factors. Then, the use of the Ni-DAS(K) factor with four S(K) factors as input data for the RMC simulations has permitted us to obtain more stable partial S(Ni-Ni)(K), S(Ni-Zr)(K) and S(Zr-Zr)(K) factors. The partial S(ij)(K) factors are very close to those reported earlier for the amorphous NiZr(2) alloy. The structural data (coordination numbers and interatomic distances) for the first neighbors for both amorphous NiZr(2) and NiZr(3) alloys are also very similar.