Numerical analyses of a Multi-layered AMR with Manganese-based Materials.

The active magnetic regenerator (AMR) is expected to contribute to realizing a practical use of the magnetic heat pump in the room temperature. The characteristics of the magnetic material used for the AMR constitute a major factor determining the performance of the magnetic heat pump equipped with the AMR. Large magnetocaloric effects (MCEs) at the room temperature have been reported in the several research papers. Magnetic materials having the first-order phase transition show large MCEs in comparison with the second order phase transition materials such as gadolinium. While the first-order materials have large MCEs, the temperature range where they function is smaller than that of the second-order materials. Therefore, the multilayered AMR is necessary for obtaining a large temperature span in case of using the first order materials. We have conducted numerical analyses of the multi-layered AMR with manganese-based materials and discussed the design of multi-layered AMR using the first order materials as preparation for the experiments. We have found out that there is a possibility that a cooling capacity of about 15 W at a temperature span of 30 K can be obtained at 17 layers and Curie temperature difference of 2.5 K for each layer. It means that a unit will have a cooling capacity of 150 W when 10 AMRs are assembled as one unit.