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, Neel temperature (T_N) 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 T_N of the material reduces gradually from 110 k to 45 k, and a splitting of T_N 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.