Numerical studies on the influence of sample inhomogeneity on the isothermal magnetic entropy change evaluated from magnetization data

Abstract

Influence of sample inhomogeneity in the form of Curie temperature distribution on the isothermal magnetic entropy change and its field dependence is studied by numerical methods, using Landau theory based equation of state with gadolinium as the model system. Results show that the nature/shape of distribution influences both the isothermal magnetic entropy change (\(\Delta S_\mathrm{M}\)) and its field dependence near the critical temperature (\(T\approx T_\mathrm{C}\)) regime. From the present study, it is found that the nature/shape of \(T_\mathrm{C}\) distribution about its mean value significantly influences the values of both maximum isothermal magnetic entropy change (\(|\Delta S_\mathrm{M}|^{\max }\)) and the corresponding temperature (\(T^\mathrm{peak}\)).