Abstract
This work focuses on the structural, magnetocaloric effect, and critical exponent investigations of La0.6Sr0.2Na0.2MnO3 manganite prepared via sol-gel method. XRD analysis confirms the rhombohedral structure with R3c symmetry for this sample, and Rietveld method was used to estimate its different structural parameters. The sample presents FM-PM phase transition of second-order type at T-C=309K. The maximum of magnetic entropy change (-SMmax) and relative cooling power (RCP) reach values of about 3.57Jkg(-1)K(-1) and 214.46Jkg(-1), respectively (at mu H-0=5T). These values indicate that La0.6Sr0.2Na0.2MnO3 sample can be used as active magnetic refrigerator. Critical exponents (beta, gamma, and delta) of the sample have studied by analyzing the M(mu H-0, T) isotherms using different techniques. The estimated values of these critical exponents are found to be different to those predicted for standard theoretical models.