Effect of off-stoichiometry and Ta doping on Fe-rich (Mn,Fe)2(P,Si) based giant magnetocaloric materials

The influence of off-stoichiometry and doping with the 5d transition metal Ta has been studied in quaternary (Mn,Fe)2(P,Si)-based compound, which is one most promising materials systems for magnetic refrigeration. It found that substitution can decrease temperature Ttr, while thermal hysteresis ∆Thys remains about constant. A low enhances magnetocaloric effect (MCE). For Mn0.6Fe1.27-yTayP0.64Si0.36 y = 0.01 entropy change ∆Sm shows enhancement 30.7% compared to undoped material a field 1 T. occupancy substitutional atoms determined by XRD DFT calculations. Ttr shift enhanced MCE upon are ascribed competition between weakening exchange interactions strengthening hybridization. Our studies provide good strategy further optimize this family.