Field Dependence of Magnetocaloric Properties in La 0.6Pr 0.4Fe 10.7Co 0.8Si 1.5

Abstract

In this paper, the field dependence of magnetocaloric properties of La 0.6Pr 0.4Fe 10.7Co 0.8Si 1.5 with second-order phase transition material is studied using a phenomenological model. The model parameters were determined from the magnetization data adjustment and were used to give better fits to magnetic transition and to calculate the magnetocaloric thermodynamic quantities. The entropy curves have been observed to behave as an asymmetrical broadening of ΔS M peak with increasing magnetic field. For larger fields, the peak shifts to higher temperatures, while the overall shape of the curve broadens over a wide temperature range. The values of maximum magnetic entropy change, full width at half maximum, and relative cooling power, at several magnetic field variations, were calculated. The maximum magnetic entropy changes of 3.957(5) and 14.197(4) J kg −1 K −1 and the relative cooling power (RCP) values of 95.420(3) and 392.729(2) J kg −1 are obtained for 1 and 5 T, respectively. The theoretical calculations are compared with the available experimental data. The critical exponents associated with ferromagnetic transition have been determined from magnetocaloric effect (MCE) methods. By using the field dependence of ΔS M max≈a(μ 0 H) n and the distance (T peak−T c)≈b(μ 0 H)1/Δ, we have investigated the critical behavior of La 0.6Pr 0.4Fe 10.7Co 0.8Si 1.5. From the analysis of the relationship between the local exponent n and the gap exponent Δ, we have calculated other exponents: β, γ, and δ. The large MCE, relatively high RCP, high magnetization, and low cost jointly make the present compound a promising candidate for magnetic refrigerant near room temperature.