Four approximations are presented for the purpose of analysing the intensity distribution of diffuse wave scattering by ordered phases. They are, in order of accuracy and mathematical complexity random phase approximation, Bethe-Peierls approximation, mean spherical approximation and improved mean spherical approximation. The third one is shown to be intimately related to, yet better than, the widely applied linearised approximation of Clapp and Moss (1966). The present theory is expected to be useful for extracting the values of the mixing energies of ordered phases from the diffuse intensity distributions of elastic wave scattering experiments.

Shinn-Tyan Wu

Papers

A theory of diffuse scattering of waves by ordered phases