Analysis and Calculation of the Magnetization, Magnetic Susceptibility and the Specific Heat Close To Phase Transitions in Heterometallics

Abstract

The temperature dependence of the magnetization for DMFeNi and DMFeCu is calculated by the molecular field theory and it is also analyzed as functions of temperature and the magnetic field by the power-law formulae close to the phase transitions in these compounds by using the observed data from the literature. From the analysis, values of the critical exponents beta (temperature-induced order parameter at H = 100 Oe) and delta (field-induced order parameter at T = 2 K) are deduced. Also, using the observed M-H data, magnetic susceptibility is calculated as a function of the magnetic field for DMFeNi and DMFeCu. Regarding the thermal properties of MOFs, the specific heat of DMFeFe, as an example, is calculated by an Ising model superimposed on an Einstein and/or Debye model using the observed C-P data from the literature. Our analyses and calculations indicate a nearly second order (or weakly first order) transition for the heterometallics studied here.