Microstructure, magnetic properties and thermal conductivity of LaFe11.2Si1.8/Ta magnetocaloric composites

Abstract

Abstract The LaFe11.2Si1.8/Ta composite materials with Ta contents of 4, 8 and 12 wt% were fabricated. The crystal structure, component, magnetocaloric property and thermal conductivity of the composite materials were detected. It is found that the addition of Ta does not change the Curie temperature and magnetic phase transition feature of LaFe11.2Si1.8/Ta composite materials. The maximal magnetic entropy change (−ΔSMmax) are 11.17, 10.71 and 10.56 J/kg·K for Ta contents of 4, 8 and 12 wt% under a magnetic field change of 0–7 T, respectively. Correspondingly, the values of relative cooling power (RCP) are 394.55, 402.91 and 408.20 J/kg. The thermal conductivity (λ) improves remarkably with increasing Ta content, and the values of λ are evaluated to be 4.49(6), 5.56(3) and 7.10(2) W/m·K for LaFe11.2Si1.8/Ta with Ta contents of 4, 8 and 12 wt% at their own Curie temperatures, respectively.