Nonequilibrium microscopic treatment of the ordering process in a solid solution

A phase transition of the type "order-disorder" has been considered in solid solutions within the framework of the electronic subsystem as a collection of quasiparticles called "concentrons" in a state with a wave vector which is equal to the wave vector k_s of the superstructure; the phase transition is due to emission of concentrons when relaxation of electronic bands of atoms on "foreign" sublattices takes place. This treatment permitted a simple description of the ordering kinetics on a microscopic level. In this work, the possibility of creation of dissipating structures in solid solutions is also discussed. Conditions for the occurrence of these structures have been analyzed. The mechanism of formation of a structure of A₂B type has been explained for the case of tempering of binary solid solutions which have a tendency to order into the CsCl structure.