Magnetocaloric properties of the La 0.7Pr 0.3Fe 13−xSi x compounds

Abstract

Magnetic entropy change Δ S m , hysteresis loss and refrigerant capacity of NaZn 13-type La 0.7Pr 0.3Fe 13− x Si x (1.5⩽ x⩽2.0) compounds have been investigated. The Curie temperature T C increases linearly with the increase of silicon concentration. Although the maximum value of Δ S m 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 T C 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 RC eff is maintained at high values of 362−439 J/kg for a field change of 0−5 T. This implies that a large Δ S m and a high RC eff can be achieved simultaneously in the La 0.7Pr 0.3Fe 13− x Si x compounds.