The temperature dependence of the diffuse scattering fine structure from disordered equiatomic CuAu was studied using {\it in situ} x-ray scattering. In contrast to Cu3Au the diffuse peak splitting in CuAu was found to be relatively insensitive to temperature. Consequently, no evidence for a divergence of the antiphase length-scale at the transition temperature was found. At all temperatures studied the peak splitting is smaller than the value corresponding to the CuAuII modulated phase. An extended Ginzburg-Landau approach is used to explain the temperature dependence of the diffuse peak profiles in the ordering and modulation directions. The estimated mean-field instability point is considerably lower than is the case for Cu3Au.
@article{arxiv.cond-mat/9810322,
title = {Temperature dependence of the diffuse scattering fine structure in equiatomic CuAu},
author = {O. Malis and K. F. Ludwig, and W. Schweika and G. E. Ice and C. J. Sparks},
journal= {arXiv preprint arXiv:cond-mat/9810322},
year = {2012}
}