Structural Transformations Far Off Equilibrium

• Main Author: O. I. Olemskoi, A. A. Katsnelson
• Format: Article
• Language: English
• Published: G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine 2002-03-01
• Series: Успехи физики металлов
• Online Access: https://doi.org/10.15407/ufm.03.01.001

Within the framework of the methods of statistical physics based on the use of the nonergodic theory and phase space with ultrametric topology, transformations of strong nonequilibrium condensed matter are studied at micro- and macroscopic structural levels. Based on the conception of rearranged potential relief, a displacement-vector partition into elastic and plastic parts is obtained. The martensitic transformation is shown to be not reducible to thermodynamic transformation, but to synergetic transition that inherent in systems far off equilibrium. On macroscopic scales, a moving off equilibrium causes ergodicity breaking, due to which the hierarchical coupling between different structure levels is appeared. Within the state space, such structures exhibit the fractal nature to be represented by means of Fourier series of atom distribution waves modulated in ultrametric space. As applications of proposed methods, we treat the following: crystal-structure evolution during polymorphic transformation of h.c.p. lattice to f.c.c. one through the stage of one-dimensional long-period structures; kinetics of low-temperature evolution of orthorhombic phase of HTSC nonstoichiometric metal oxides through the stage of homological structures; peculiarities of direct and backward transformations of crystal and defect structures of the palladium during its saturation by hydrogen and degassing process; peculiarities of the martensitic transformation (athermic character and freezing in macrostructure rearrangements, combination of both determinancy and stochasticity, different manifestation of hysteresis, explosive-like transformation at incomplete cycling, structure-dependent defect of modulus, nontrivial manifestation of the memory effect, peculiarities of acoustic emission). On the basis of analysis of a fractal structure of thermodynamic-potential distribution in a configuration space, peculiarities of time asymptotics of the structure factor are revealed.