Temperature dependent microstructure of Cu3Au in the disordered phase

We have investigated the temperature dependent fine structure of the equilibrium diffuse X-ray scattering of a Cu,Au(110) crystal. The diffuse scattering exhibits a marked temperature dependence for the fourfold peak splitting around the diffuse maxima at the superlattice reflection positions associated with Fermi surface imaging. The separation of the split diffuse maxima increases with temperature corresponding to a proliferation of correlated microdomains in a real space picture, In this paper the temperature dependence of the positions of the diffuse peaks is directly related to he temperature- and wavevector-dependent alloy self-energy. At relatively high temperatures this behavior can be described by taking into account first corrections to the Krivoglaz-Clapp-Moss approximation.