Structure and Inverse Magnetocaloric Effect of Mn_(1.2)Co_(0.8)Si_(0.2)P_(0.8) Compound Prepared by SPS

摘要

The single-phase Mn_(1.2)Co_(0.8)Si_(0.2)P_(0.8) compound was fabricated by the spark plasma sintering (SPS) technology followed by vacuum annealing. The microstructure, Néel temperature (Tn) and "inverse" magnetocaloric effect of this compound were investigated. The results show that the structure of Mn_(1.2)Co_(0.8)Si_(0.2)P_(0.8) compound prepared by SPS is a single phase with precise stoichiometric proportion. Increasing the magnetic field from 0.05 T to 1 T, the Tn of the material reduces gradually from 110 k to 45 k, and a splitting of Tn appears. The splitting of the antiferro-to-ferromagnetic transition is an intrinsic feature rather than the secondary phase. Though the maxima entropy changes is about 0.6 Jkg~(-1)K~(-1) at B=5T, the Mn_(1.2)Co_(0.8)Si_(0.2)P_(0 .8) phase synthesized by SPS is more favorable, more overall magnetic moment. In addition to the magnetic refrigeration applications, this compound may be used in thermomagnetic generators.