Optimization of the refrigerant capacity in multiphase magnetocaloric materials

The refrigerant capacity (RC) of magnetocaloric materials can be enhanced using multiphase materials or composites, which expand the temperature range over which a significant magnetic entropy change can be obtained. Numerical simulations show that by controlling the parameters of the composite (the fraction of the different phases and their Curie temperatures) improvements of RC of similar to 83% are possible. The maximum applied field plays a crucial, nonmonotonic, role in the optimization. As a proof of concept, it is shown that the combination of two Fe(88-2x)Co(x)Ni(x)Zr(7)B(4)Cu(1) alloys produces an enhancement in RC of similar to 37%, making it similar to 92% larger than that of Gd(5)Si(2)Ge(1.9)Fe(0.1). (C) 2011 American Institute of Physics. [doi:10.1063/1.3560445]