Critical Behavior Near the Paramagnetic to Ferromagnetic Phase Transition in (La 0 . 6 Ca 0 . 4 MnO3)/x(CuO) Ceramic Composites

Abstract

We report magnetic properties of (La0.6Ca0.4MnO3)/x(CuO) compounds in terms of isothermal magnetization analysis and scaling behavior with various critical exponents in the vicinity of the PM to FM transition region. According to the Banerjee criterion, we found that the FM–PM phase transition is the type of SOMT. Moreover, the critical exponents β, γ, and δ are determined using the modified Arrott-plot (MAP), the Kouvel–Fisher method (KF), as well as the critical isotherm (CI) analysis. The estimated results are close to those expected for three-dimensional Heisenberg class with short-range interaction. From the field dependence of RCP and ΔSM, it was possible to evaluate the critical exponents of the magnetic phase transition. These values are in good agreement with those obtained from the critical exponents using the Kouvel–Fisher plot (KF). Finally, we used the scaling hypotheses to scale the heat capacity changes to a single universal curve for (La0.6Ca0.4MnO3)/x(CuO) composites.