LaFe11.6Si1.4/Pr40Co60 magnetocaloric composites for refrigeration near room temperature

Abstract

The effect of Pr40Co60 addition on the structure, thermal conductivity, magnetic, magnetocaloric and mechanical properties of sintered LaFe11.6Si1.4/Pr40Co60 bulk composites were investigated. The addition of Pr–Co alloy has important effects on these properties due to the diffusion of Pr and Co into the La(Fe,Si)13 phase during sintering. After 6 h of sintering at 1373 K, these composites exhibited a gradual increase in Curie temperature (TC) from 220 K to near room temperature with relatively large maximum magnetic entropy change (–∆SM)max of 2.7–2.9 Jkg–1 K–1 under 0–2 T external magnetic field change. The diffusion of Pr and Co atoms into 1:13 majority phase facilitates 1:13 phase formation, while the Co content of the Pr-Co binder could be used to tune the TC but resulting in the reduced (–∆SM)max in the composites. The composites exhibit high compressive strength (σbc)max of up to 550 MPa and thermal conductivity (λ) of up to 10.64 Wm–1 K–1. Thus, these materials are promising candidates for near room temperature refrigeration.