Superior comprehensive properties of LaFe11.8Si1.2/Ce60Co40 magnetocaloric composites

LaFe11.8Si1.2/10 wt%Ce60Co40 composites were prepared by spark plasma sintering and subsequent diffusion annealing. A novel core–shell structure is observed with the LaFe11.8Si1.2 particles as the core and the (La,Ce)2(Fe,Co,Si)17 (2:17) phase as the shell. As diffusion annealing time (ta) increases, this core–shell structure is replaced by the formation of the (La,Ce)1(Fe,Co,Si)13 phase. Annealing at 1323 K for 12 h results in samples with (−ΔSM)max of 9.30 J/(kg·K) (Δμ0H = 2 T), good mechanical properties ((σbc)max = 402 MPa, ε = 4.21%) and thermal conductivity of 8.7 W/(m·K). Thus, bulk composites with excellent comprehensive properties for magnetic refrigeration are obtained in this work.