La0.6Ca0.2Na0.2MnO3 Perovskite: Structural, Magnetic, Critical, and Magnetocaloric Properties

The results of structural, magnetic, critical, and magnetocaloric characterizations of La0.6Ca0.2Na0.2MnO3 perovskite have been reported. XRD analysis of the sample synthesized using sol-gel method shows good crystallization in the R3 over bar rhombohedral structure. From M(T) curve, a second-order ferromagnetic-paramagnetic (FM-PM) phase transition appears at the Curie temperature (T-C) around 275 K. Critical exponents (beta, gamma, and delta) have been evaluated using different techniques such as modified Arrott plots (MAP), Kouvel-Fisher (KF) method, and critical isotherm (CI). We found that the critical exponents of the prepared sample agree well with those of the mean-field model. We have also estimated the magnetic entropy change (-Delta S-M) and relative cooling power (RCP) for the sample which obey power laws as - increment S-M = a(mu H-0)(n) and RCP = A(mu H-0)(N), respectively. Delta S-M and RCP values were relatively higher, making the sample promising candidate for magnetic refrigeration technology. The estimated values of the magnetic ordering parameters (n and N) are used to confirm the reliability of the evaluated critical exponent.