Experimental evaluation of a single layer MnFeP1-xSi x AMR.

First order magnetocaloric materials (FOM) have desirable characteristic such as a high magnetocaloric effect, large heat capacity and use inexpensive constituents. However, irreversibilities associated with thermal and magnetic hysteresis, the strong dependency of the specific heat with temperature and magnetic field, and the narrow temperature range of useful magnetocaloric effect require further investigation. Among the the MnFeP1-xSix system is one of the promising materials for magnetic heat pumps applications near room temperature. The present paper describes the experimental investigation of a single-layer MnFeP1-xSix active magnetic regenerator (AMR), under different test conditions and following a protocol of heating and cooling processes. The results for the FOM are compared with a Gd AMR, that is experimentally tested following the same protocol, with the objective to study the irreversibilities associated with FOM.