Magnetism and magnetocaloric effect of multicomponent rare earth intermetallic hydride Gd0.2Tb0.2Dy0.2Ho0.2Er0.2NiH1.4

Multicomponent Gd0.2Tb0.2Dy0.2Ho0.2Er0.2Ni (orthorhombic, FeB-type, space group Pnma, no. 62, oP8) compound with high-entropy substitution at the rare earth (R) site of RNi phase orders ferromagnetically at ∼66 K (TC). The hydride sample Gd0.2Tb0.2Dy0.2Ho0.2Er0.2NiH1.4 (orthorhombic, FeB-type) is nanocrystalline and it undergoes a paramagnetic to ferromagnetic order at ∼6 K. From the magnetization vs field (M-H) data, isothermal magnetic entropy change (ΔSm) is calculated. A maximum ΔSm value of −13.1 J kg−1 K−1 is obtained for 70 kOe field change at 8 K. Thus, magnetocaloric effect is slightly reduced in hydride when compared to −16.4 J kg−1 K−1 at 62.5 K in the parent Gd0.2Tb0.2Dy0.2Ho0.2Er0.2Ni compound.