Crossover of critical behavior and magnetocaloric effect in FePd2Te2 with one-dimensional Fe chains

Abstract

Recently, a two-dimensional ferromagnet FePd2Te2 exhibiting easy-plane anisotropy with a quasi-one-dimensional spin system has been discovered. We report the magnetic critical behavior and magnetocaloric effect of FePd2Te2 single crystals with magnetic fields applied both in-plane and out-of-plane. Conventional iterative methods failed to determine the critical exponents of the material. Using a modified iterative method, we obtained two sets of critical exponents on both sides of the critical temperature TC: for the in-plane magnetic field direction, β−=0.7155 and γ−=1.0255 below TC and β+=0.6205 and γ+=0.9005 above TC. The reliability of the estimated critical exponents is confirmed through scaling analysis. Under a 7 T magnetic field applied near TC, the maximum entropy change (−ΔSMmax) is 1.38 J kg−1 K−1 and the relative cooling power (RCP) is 73.95 J kg−1. The critical exponents extracted using the magnetic entropy scaling analysis exhibit good consistency with those obtained from the analysis of magnetization isotherms. The renormalization group theory analysis of the critical exponents reveals that FePd2Te2 exhibits long-range magnetic interactions intermediate between the 3D Heisenberg model and mean-field model, displaying weak itinerant ferromagnetism due to the presence of itinerant electrons.