The present work is devoted to the creation of a theoretical approach for a full description of structural, magnetic, and magnetostructural phase transitions in solid-state materials using data taken from experimental graphs of temperature dependences of order parameters of magnetization and deformation. The method is based on the analytical calculation of structural, magnetic, and magnetostructural coefficients in the expansion of the Landau thermodynamic potential in terms of order parameters up to the fourth degree, followed by the construction of dependences in the full temperature range, including all phase transitions and phases at low magnetic fields. An Ni50.7Mn33.4In15.6V0.3 alloy of the Heusler family was used for research.
Morozov et al. (2025) studied this question.