Kosogor A. Theory of ferroelastic phase transitions in crystals with defects

The thermodynamic theory that enabled the calculation of the value of practically important physical effects connected with ferroelastic phase transitions in crystals with defects was developed in the thesis. This enabled the introduction of interrelation of crystal lattice atoms and crystal defects, and for the first time two fundamental tasks of solid state physics were solved, i.e. the quantitative description of: a) the influence of spontaneous or mechanically-induced deformation of crystal lattice on the spatial distribution of crystal defects; b) the deformation of crystal lattice due to the spatial redistribution of defects or atoms specially introduced in the crystal lattice. As a result of these tasks solution, at first, the conception of internal mechanical stresses, omnipresent in real crystals, was theoretically substantiated and the wide spectrum of properties of shape memory alloys was quantitatively described, and at second, the theoretical solubility curves of hydrogen in bulk specimens and films of vanadium were computed.