PAIR INTERACTIONS IN ALLOYS EVALUATED FROM DIFFUSE-SCATTERING DATA

The theory of short-range order in alloys developed previously by the present authors is used to resolve the ambiguities existing in the problem of determination of pair potentials from diffuse-scattering measurements. It is shown that in the framework of the Krivoglaz-Clapp-Moss approximation the best results correspond to the Krivoglaz normalization. They turn out to be identical to those of the spherical model, a zero-order approximation of the theory under consideration. The origin of the self-interaction potential appearing in this case is clarified. All attempts at normalizing Krivoglaz's formula in order to preserve a sum rule or prevent the occurrence of self-interaction result in a distortion of the potentials. A higher-order approximation is used to explain the remaining disagreement between the results obtained by means of the Krivoglaz formula and the inverse Monte Carlo method.