Simulation of Atomic Configurations in Short Range Ordered Ni3Fe

A procedure similar to that of Gehlen and Cohen and Williams is used to simulate atomic configurations of short range ordered Ni3Fe. The short range order parameters were previously measured after different heat treatments. Probabilities of different clusters are computed from those models: triangles, tetrahedrons, clusters as defined by Clapp. These probabilities vary with the enhancement of short range order. It is shown that most of the clusters the probabilities of which increase with short range order, are directly related with the L12 ordered structure: either they have the L12 structure, or the L12 structure modified by one or two antiphase boundaries. Such clusters are identified in the model in order to display perfectly ordered domains.