Electron Diffraction Study on Diffuse Scattering from Disordered Cu 3 Au Alloy

A detailed study has been made on diffuse scattering from Cu 3 Au alloy in the disordered state by electron diffraction, using single crystal evaporated films, in order to investigate the origin of the short-range order above T c . Aspects of the diffuse scattering resemble in some respects those of superlattice reflections below T c which are related to the antiphase domain structure. From the present study, however, it has become clear that there is no direct relation between the short-range order state above T c and the antiphase domain structure below T c . Behaviors of the diffuse scattering have been studied, the electron-atom ratio being changed by addition of Pd or In to Cu 3 Au. Results obtained are well interpreted by the suggestion of Moss, indicating that the short-range order state revealed by the diffuse scattering originates from anomalies of energy of conduction electrons.