Magnetocaloric properties of the La0.7Pr0.3Fe13−xSix compounds

Magnetic entropy change ΔSm, hysteresis loss and refrigerant capacity of NaZn13-type La0.7Pr0.3Fe13−xSix (1.5⩽x⩽2.0) compounds have been investigated. The Curie temperature TC increases linearly with the increase of silicon concentration. Although the maximum value of ΔSm under a field change of 0−5 T decreases from 30.5 to 11.4 J/kg K as x increases from 1.5 to 2.0, the hysteresis loss at TC reduces remarkably from 89.2 J/kg for x=1.5 to zero for x=2.0 because the increase of Si content can weaken the itinerant electron metamagnetic transition. The effective refrigerant capacity RCeff is maintained at high values of 362−439 J/kg for a field change of 0−5 T. This implies that a large ΔSm and a high RCeff can be achieved simultaneously in the La0.7Pr0.3Fe13−xSix compounds.