Mn-based Compounds as Magnetic Refrigerant Materials near Room Temperature

The Mn-based compounds with the Fe2P-type structure undergo a first-order magnetic transition near room temperature. Since these compounds exhibit giant magnetocaloric effects, they are expected to be promising candidates for magnetic refrigerant materials. In this paper, we show our recent experimental data on the magnetocaloric properties of MnFeP1-xSix. It is found that the refrigeration capacity, q, of MnFeP1-xSix with the temperature span of 30 K is 1.5-1.9 times as large as that of the conventional magnetic refrigerant, Gd. In order to obtain higher cooling capacity, a composite material is proposed.