Synthesis of magnetocaloric LaFe11.6Si1.4 alloy by spark plasma sintering

Abstract

LaFe11.6Si1.4 alloys have been successfully fabricated by spark plasma sintering (SPS). An annealing study of the SPS LaFe11.6Si1.4 alloys at different temperatures ranging from 1373 to 1523 K for annealing times from 30 minutes to 72 hours was carried out. This annealing study showed that LaFe11.6Si1.4 samples annealed at 1473K (for annealing times between 30 minutes and 6 hours) have a significantly higher amount of the NaZn13-type phase compared to samples annealed at other temperatures. Thus the critical annealing temperature which enhances the formation of the NaZn13-type phase in SPS LaFe11.6Si1.4 compounds is 1473K. A second study investigated the effect of different particle sizes of the starting powders on the formation of the NaZn13-type phase. This study found that the samples synthesized using larger sized powder particles exhibited a significantly higher amount of the NaZn13-type phase compared to samples synthesized using smaller sized powder particles, for the same heat treatment.