Enhanced magnetocaloric effects and tunable thermal hysteresis in transition metal pnictides

The effect of Co and Ni substitutions for Fe on the magnetocaloric properties of MnFe(P,Ge) compounds crystallizing in the hexagonal Fe2P type of structure was studied. It was found that, by changing composition, a small thermal hysteresis and a giant magnetocaloric effect can be obtained simultaneously in MnFe(P,Ge) compounds when the magnetic transition is controlled to be close to the border separating the first- and second-order transition regimes.