Anisotropic magnetocaloric effect in Fe3−xGeTe2
Abstract We present a comprehensive study on anisotropic magnetocaloric porperties of the van der Waals weak-itinerant ferromagnet Fe 3− x GeTe 2 that features gate-tunable room-temperature ferromagnetism in few-layer device. Intrinsic magnetocrystalline anisotropy is observed to be temperature-dependent and most likely favors the long-range magnetic order in thin Fe 3− x GeTe 2 crsytal. The magnetic entropy change Δ S M also reveals an anisotropic characteristic between H // ab and H // c , which could be well scaled into a universal curve. The peak value $$-\Delta {S}_{M}^{{\max }}$$ − Δ S M max of 1.20 J kg −1 K −1 and the corresponding adiabatic temperature change Δ T ad of 0.66 K are deduced from heat capacity with out-of-plane field change of 5 T. By fitting of the field-dependent parameters of $$-\Delta {S}_{M}^{{\max }}$$ − Δ S M max and the relative cooling power RCP, it gives $$-{\rm{\triangle }}{S}_{M}^{{\max }}$$ − ∆ S M max ∝ H n with n = 0.603(6) and RCP ∝ H m with m = 1.20(1) when H // c . Given the high and tunable T c , Fe 3− x GeTe 2 crystals are of interest for fabricating the heterostructure-based spintronics device.