Mechanism and kinetics of phase transitions and other reactions in solids

Abstract: The work is presented, leading to the universal contact molecular mechanism of phase transitions and other reactions in solid state. The two components of the mechanism - nucleation and interface propagation - are investigated in detail and their role in the kinetics is specified. They were shown to be peculiar: nucleation is "pre-coded", rather than resulted from a successful fluctuation, and the interface propagates by molecular filling of thin layers in the transverse direction. The structure of the nucleation sites is determined. The inherent instability and irreproducibility of the kinetics in question is revealed. A linear kinetics, as opposed to the bulk kinetics, is introduced and shown to be in accord with the contact mechanism. Ferromagnetic phase transition and magnetization are added to the list of solid-state reactions; neither occurs without structural rearrangement.