Structural and Magnetocaloric Properties of MnFeP1−xSix Compounds Prepared by Spark Plasma Sintering

Crystal structure and magnetic properties have been studied for bulk MnFePSi compounds prepared by the spark plasma sintering method. The effect of Si content on the crystal structure and the magnetic properties of the compounds were investigated. The MnFePSi compounds crystallize in a hexagonal Fe₂P-type structure without obvious secondary phase. Magnetic measurements indicate that the compounds undergo a ferromagnetic to paramagnetic first-order transition near their Curie temperature (T_C). With the increase in Si content, the T_C rises from 343 to 381 K, while AThys decreases simultaneously from 27 to 15 K. For MnFeP_0.5Si_0.5 compound, the magnetic entropy change (-ΔS_M) for a magnetic field change from 0 to 3 T is 12 J/kg· K, demonstrating its good potential for practical application.