LAUSR

Abstract The structure of Ni 50 V 50 amorphous alloy was investigated by using neutron, X-ray diffraction and reverse Monte Carlo (RMC) modelling. The RMC configuration was decomposed into polyhedral holes whose faces are all triangles consisting of chemical bonds. Free volumes in the respective polyhedral holes were evaluated with reference to the packing efficiency of Ni-V metastable BCC phase. The tetrahedral holes, which account for about 70% of the whole space, are regarded as densely packed units because the average packing efficiency of them is approximately equal to that of the corresponding crystal phase. On the other hand, various types of polyhedral holes, which have a certain free volume, are observed and some of them are connected with each other. The densely packed coordination polyhedra consisting only of tetrahedral holes tend to be clustered.