COP of cooling cycles around the AF-F transition in FeRh based on experimental data

By the heat capacity of the FeRh alloy when heating in the AF-F transition region in zero magnetic field and the change in the temperature of the alloy when the transition is adiabatically induced by applying magnetic field and the reverse transition is adiabatically induced by removing magnetic field measurement data, the entropy-temperature diagram of the alloy when heating and cooling in various magnetic fields up to 2.5 T is constructed. Using this diagram, the cooling cycles based on adiabatic inducement of the transition by magnetic field are built up. The values of the coefficient of performance of the cycles obtained from the diagram have been found to be ranging from 37 to 55 in particular in a 2.5 T field, which is close to the ones calculated by the model entropy-temperature diagram of the alloy drawn up under the assumption that the transition is ideally isothermal.