High Magnetic Anisotropy and Magnetocaloric Effects in Single-Crystal Cr₂Te₃

Abstract

We report a systematic investigation of anisotropic magnetocaloric effects in single-crystal Cr 2 Te 3 . Single-crystal samples are synthesized by chemical vapor transport and characterized by X-ray and Laue diffraction methods. The maximum magnetic entropy change −ΔS M max is 4.50 J kg −1 K −1 for the easy c-axis (3.36 J kg −1 K −1 for the hard axis along ab-plane), and the relative cooling power (RCP) is 296.7 J kg −1 for the easy c-axis (183.84 J kg −1 for the hard axis along abplane) for a magnetic field change of 9 T near the Curie temperature. The magnetocrystalline anisotropy constant K u is estimated to be 580.12 kJ m −3 at 140 K, decreasing to 148.60 kJ m −3 at 168 K. Meanwhile, the maximum of the rotational magnetic entropy change −ΔS M R (T, H) between the c-axis and the ab-plane is about 1.14 J kg −1 K −1 for magnetic-field change of 9 T. The critical exponents are estimated by analyzing magnetocaloric effects, which indicate a 2D-Ising type magnetic system. The accuracy of estimated critical exponents is verified by scaling analysis. The maximum magnetic entropy change −ΔS M max ≈ 5.25 J kg −1 K −1 (along the c-axis) and the corresponding adiabatic temperature change ΔT ad ≈ 3.31 K (along the c-axis) are estimated by analyzing heat capacity measurements with a magnetic field up to 9 T.