Multicaloric effect in FeRh, exploiting the thermal hysteresis in a multi-stimuli cycle combining pulsed magnetic field and uniaxial load.

Large magnetocaloric effects can be observed in materials with first-order magneto-structural phase transition. However, materials with large thermal hysteresis show a reduced effect in moderate fields (∼ 2 T) because the external field is insufficient to induce a fully reversible transformation. The hysteresis can be overcome or even exploited by applying a second external stimulus. A multi-stimuli test bench has been built to demonstrate the multicaloric effect in FeRh alloy using a pulsed magnetic field up to 9 T and a uniaxial stress of up to 700 MPa. A cyclic multicaloric effect of ± 2.5 K could be observed for a sequential application of a pulsed field of 3 T and a uniaxial stress of 700 MPa. The interplay among external field strength, thermal hysteresis, and the transition width enables the use of pulsed magnetic fields and allows a decoupling of the applied magnetic field and the heat transfer process in the multi-stimuli cycle. [ABSTRACT FROM AUTHOR]