Neutron scattering study on the kinetics of clustering in CuNi alloys

This paper describes an investigation of the kinetics of clustering (preference for like nearest neighbors) in a number of CuNi alloys. The kinetics was studied by measuring the evolution of the diffuse neutron-scattering cross section with time. In order to maximize the diffuse scattering, the isotopes ${}_{}{}^{62}{}_{}{}^{}\mathrm{Ni}$ and ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$ were used. The experimental results are compared with a theoretical model based on the lattice diffusion theory of spinodal decomposition. Good agreement is obtained for long-wavelength composition fluctuations. For short wavelengths agreement is not quite satisfactory. Values of thermodynamic and kinetic parameters deduced from the experiments are in good agreement with data obtained with different techniques at high temperatures.