Hysteresis of martensitic phase transformation in the shape memory alloy: thermodynamic aspect

  V. A. L'vov, Taras Shevchenko National University of Kyiv, Ukraine

1. The state of art:
   1. "ordinary" transformational behavior of the shape memory alloy;
   2. quasi-second-order martensitic transformations;
   3. martensitic transformations with wide hysteresis loops,high-temperature superelasticity.
2. Gibbs potential of the shape-memory alloy:
   1. Landau-Devonshire model and its non-applicability to MTs;
   2. symmetry-conforming Gibbs potential and the role of the third-order terms in the strain tensor components.
3. Mechanica stresses as the factor of strong influence on the hysteresis of MT:
   1. "external" and "internal" stressing of the crystal lattice;
   2. the influence of axial stress on the hysteresis of MT, quasi-second order MTs;
   3. the influence of isotropic expansion of crystal lattice, high temperature superelasticity.

BIO Victor A. L’vov Current position: professor in National Taras Shevchenko University, Kyiv, Ukraine Research Fields: Phase transitions Theory, Materials Science Current and Previous Researches: functional properties of shape memory alloys; magnetic thin films; phase transitions in ferro- and antiferromagnetic solids, magnetic domain structures and magnetoelectric effect. Scientific cooperation with: Professor Cesari (University of Balearic Islands, 2000 -  present); Professor Simo-Pekka Hannula (Technological University of Helsinki, 2004 - 2012); Professor Jose Manuel Barandiaran, Professor Volodymyr Chernenko (Universidad del Pais Vasco, 2010 - present); Professor Gregory Gerstein (Leibnitz University, Hannover, 2016 -  present) Methodological and Technical Expertise: 2008 – present Member of Specialized Council for the expertise of Ph.D. and D.Sci. thesis’s in the Institute of Magnetism, Kyiv, Ukraine. Member of the reviewer staffs of scientific journals edited in Europe and USA. Ph.D supervision: i) Ph.D. thesis of A. O. Kosogor " The thermodynamic theory of stabilizing and destabilizing processes of martensitic phases in shape memory alloys"; ii) Ph.D. thesis of S. P. Zagorodniuk "Magnetoelastic model of ferromagnetic martensites Ni-Mn-Ga"; iii) Ph.D. thesis of V. M. Kniazkyi "Theory of thermoelastic and magnetic properties of the Ni-Mn-Ga single crystals and films"; iv) Ph.D. thesis of E. V. Gomonaj "Phenomenological Theory of Phase Transitions in the Perovskite-Type Antiferromagnets with Triangular Spin ordering".