Attractive properties of magnetocaloric spark plasma sintered LaFe11.6Si1.4/Pr2Co7 composites for near room temperature cooling applications

A series of LaFe11.6Si1.4/xwt%Pr2Co7 (x = 0, 5, 10) composites, with a range of particle size of LaFe11.6Si1.4 powders, were successfully fabricated by spark plasma sintering (SPS), followed by annealing. The influence of the particle size of the LaFe11.6Si1.4 powders and the Pr2Co7 binder content on the phase constitution, microstructure, thermal, mechanical, magnetic and magnetocaloric properties were studied. The Pr2Co7 binder content (10 wt%) and the particle size of LaFe11.6Si1.4 powders (100–200 µm) were chosen to be conducive to the formation of the desired 1:13 phase. The magnetic and magnetocaloric properties were influenced by the synergistic effects of Pr and Co atomic diffusion as well by the particle size of the LaFe11.6Si1.4 majority phase powders. The values of TC, (ΔSM)max and RC for the sample could be tuned in the range of 230–297 K, 1.90–3.70 J/kg·K and 84–149 J/kg (ΔH=2 T), respectively, by tuning the Pr2Co7 content and the particle size of the LaFe11.6Si1.4 powders. Significantly, this TC range covers a wide variety of near room temperature cooling applications. The excellent values of thermal conductivity, maximum compressive strength and strain were in the range of 14–20.90 W/m·K, 930–1405 MPa and 5.9–7.9%, respectively. These features make these materials very promising candidates for near room temperature magnetic cooling applications.