Theoretical Work in Magnetocaloric Effect of LaFe13−xSi x Compounds

Abstract

In this paper, the magnetocaloric effect (MCE) of LaFe13−xSix compounds with 1.2 ≤ x ≤ 2.2 has been investigated. For this purpose, the magnetization dependence on the temperature and magnetic field were measured. Magnetic entropy change (−ΔSM) allowing estimation of the MCE was determined based on thermodynamic Maxwell’s relation. The experimental results show that TC increases with the Si content, whereas the magnetic entropy variation decreases. A large magnetic entropy change has been observed. The maximum \((-\Delta \mathrm {S}_{\mathrm {M}}^{\text {max}})\) of LaFe10.8Si2.2 occurring close to TC = 240 K is about 2.3 Jkg−1 K−1 for an applied field change of 0–2 T. In addition, a magnetocaloric effect of LaFe13−xSix compounds (x = 1.2 and 1.6) has been also carried out using phenomenological model. Dependence of the magnetization on temperature variation for LaFe13−xSix compounds (x = 1.2 and 1.6) in different applied magnetic fields was simulated. The values of maximum entropy change, full width at half maximum, and relative cooling power (RCP) for the LaFe11.8Si1.2 and LaFe11.4Si1.6 compounds in different applied magnetic fields were calculated.