Anisotropic magnetic entropy change and magnetic critical behavior in van der Waals Fe3GaTe2

Abstract

Fe₃GaTe₂, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe₃GaTe₂ single crystal. Owing to the large anisotropy, magnetic entropy change $\left(-\Delta S_M\right)$ shows anisotropic character with $-\Delta S_M^{\max }$ of 1.67 J kg⁻¹ K⁻¹ along the c axis and 1.11 J kg⁻¹ K⁻¹ in the ab plane under field change of 5 T. The rotating $\Delta S_M$ from the ab plane to the c axis reaches 0.67 J kg⁻¹ K⁻¹ at magnetic field of 5 T. By carefully fitting the $-\Delta S_M^{\max }$ and relative cooling power (RCP), we determine their relationships to be $-\Delta S_M^{\max }\propto H^n$ (n = 0.694(1)) and $RCP\propto H^m$ (m = 1.301(3)) for the magnetic field along the c-axis. Further analysis of critical behavior near T_C reveals critical exponents β = 0.41(1) at T_C = 341.5(1) K, γ = 1.01(1) at T_C = 341.6(3) K, and δ = 3.67(15) at T_C = 340 K, indicating a three-dimensional complex magnetic exchange.