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Information × Registration Number 0220U100317, 0117U000433 , R & D reports Title Thermodynamic and magnetic-resonance properties of functional materials with magnetic-structural phase transformations. popup.stage_title Head Bar'yakhtar Victor G., Доктор фізико-математичних наук Registration Date 15-01-2020 Organization Institute of Magnetism of the National Academy of Sciences of Ukraine and Ministry of Education and Sciences of Ukraine popup.description2 The conditions of induction of the phase transition from ferromagnetic to superparamagnetic state by the martensitic transformation and magnetoelastic interaction have been obtained. The influence of this transition on the static magnetic properties of a material is described. The conditions of occurrence of phase transitions of the "quasi-second" kind due to the increase of magneto-elastic interaction during martensitic phase transformations were analyzed. The influence of magneto-structural transformations from ferromagnetic to superparamagnetic state on the magnetocaloric effect and dynamic characteristics of magnetoelastic oscillations has been evaluated. Two essentially different modes of shape memory alloy deformation behavior have been theoretically predicted and experimentally validated. The first mode is the ordinary elastic loops that show a noticeable hysteresis of stress-induced martensitic transformations observed below the critical temperature. The second mode is a giant deformation without hysteresis observed at temperatures above the critical one. The process is characterized by a highly nonlinear strain dependence, which reflects the postcritical state of the alloy and the abnormally low values of the modulus of elasticity.   Product Description popup.authors Bar'yakhtar Victor G. Danylevych Oleksandr H. Kosogor Anna O. Lvov Viktor A. popup.nrat_date 2020-04-02 Close