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Information × Registration Number 0216U008303, 0112U001009 , R & D reports Title The theory of sound and spin waves in the vicinity of phase transitions in the lattice. popup.stage_title Head Baryakhtar V, Ivanov, Registration Date 23-12-2016 Organization Institute of magnetism of NASU popup.description2 The phenomenological theory which describes the interaction of sound and spin waves with taking into account of their dissipation in the magnetically ordered materials with shape memory effect was constructed. The spectra of coupled magnetoacoustic waves, taking into account both exchange and relativistic interactions in the crystal, were obtained. The behaviour of these spectra in the vicinity of phase transitions in a lattice, namely, in the vicinity of the martensitic phase transformations was analysed. The sharp increase of the magnetoelastic interaction in the vicinity of phase transitions in the lattice, resulting in a sharp decrease in the elastic moduli of the shape memory alloy in the vicinity of such phase transition was theoretically grounded. The influence of magnetic ordering and uniform magnetostriction on the elastic moduli of the shape memory alloys was theoretically, explained and evaluated. A phenomenological model for the description of martensitic transformations, which allows you to simulate the impact of internal and external mechanical stresses on the magnetic, elastic and thermodynamic properties of the shape memory alloys was created. The internal stresses dependances on the concentration of crystal defects was obtained. A theoretical study of temperature and time dependences of the basic thermodynamic functions in the vicinity of martensitic phase transformations in the shape memory alloys was carried out. Product Description popup.authors Бар'яхтар В.Г. Данилевич О.Г. Косогор А.О. Львов В.А. popup.nrat_date 2020-04-02 Close