Parameters of the Short-Range Order Relaxation Kinetics and Interactions of Atoms in Binary Substitutional F.C.C. Solid Solutions According to the Data About Time Evolution of Diffuse Scattering of Radiations

摘要

The Khachaturyan's microscopic approach is considered, which relates a time dependence of the short-range order to diffusion of atoms and allows to use the data of measurements of time dependence of diffuse scattering intensity of radiations in a single crystal of a solid solution for calculation of both probabilities of elementary atomic diffusive jumps per unit of time into different sites of a lattice and diffusion coefficient. The kinetics of a relaxation of above-mentioned intensity for a binary solid solution can be described by kinetics models with one, two or three relaxation times. As revealed for f.c.c. -Fe-Ni permalloy as an example using the one-relaxation-time model for a calculation of equilibrium intensity values, the magnetic contribution to the 'mixing' energy of this alloy hinders its atomic ordering, and the presence of atoms with different spins causes its discontinuous phase transition from a paramagnetic state into magnetic one.