Ferroelectrics, cilt.600, sa.1, ss.73-87, 2022 (SCI-Expanded)
© 2022 Taylor & Francis Group, LLC.Temperature dependence of the magnetization M(T) is calculated for [NH2 NH3][M(HCOO)3] (M=Fe, Mn), namely, HyFe (perovskite and chiral) below (Formula presented.) =12.5 K and, for HyMn (chiral) below and above (Formula presented.) =7.9 K (at 100 Oe) by the molecular field theory (MFT). Close to the magnetic transition temperature ((Formula presented.)), the temperature (at 100 Oe) and the field (at 2K) dependence of the magnetization M(T, H) is analyzed by the power–law formula using the literature data. Magnetic susceptibility is predicted as a function of the field (T = 2K). Also, the temperature dependence of the heat capacity is calculated by the compressible Ising model close to the structural phase transitions in perovskite ((Formula presented.) =347 K) and chiral ((Formula presented.) =336 K) HyFe and the chiral ((Formula presented.) =296 K) HyMn. Our results indicate that HyM (M=Fe, Mn) exhibit weak first order or near second order transitions (magnetic transition and the structural phase transitions).