Direct measurement of the magnetocaloric effect in MnZnSb intermetalic compound

Abstract The equiatomic intermetallic alloy MnZnSb with a tetragonal Cu 2 Sb-type crystal structure (space group P4/nmm) was melted in the resistance furnace in the evacuated quartz ampoule. The adiabatic temperature change ( Δ T ad ) and the isothermal variation of the magnetic entropy ( Δ S M ) of the MnZnSb compound near to the magnetic phase transition were studied. The Δ T ad in a magnetic field up to 1.25 T was studied by the direct method. It was found that temperature dependencies of both Δ T ad and Δ S M show a sharp peak near room temperature with a maximum at Curie temperature T C  = 317 K. It was shown that there is no temperature hysteresis of the Δ T ad in MnZnSb, and the maximum of Δ T ad when the compound is heated or cooled is detected at the same temperature. The estimated value of Δ T ad in a field of 14 T is 4.5 K. It was shown that near the Curie temperature, the field dependence of the maximum of magnetic entropy change is adequately described by the thermodynamic Landau theory for magnetic second-order phase transitions.