Multiple magnetic transitions and magnetocaloric effect of Tb4CoIn alloy

Abstract

We report on the magnetic, magnetocaloric, thermal, and electrical transport properties of Tb4CoIn alloy, which crystallizes in two phases, Tb6Co2.1In0.8 (space group Immm) and Tb2In0.9Co0.1 (space group P63/mmc), respectively. The alloy reveals three successive magnetic transitions around T1 (163 K), T2 (50 K), and T3 (29 K), respectively, associated with paramagnetic to ferromagnetic transition and two sequential antiferromagnetic transitions. The low-temperature transition T3 follows the first-order magnetic behavior and exhibits the field-induced magnetic transition. Meanwhile, T2 and T1 are found to be second-order in nature which opens a possibility for hysteresis-free magnetocaloric application. The magnetocaloric properties are determined using different magnetocaloric figures of merits such as –ΔSM, ΔTad, RCP, and TEC (10). Additionally, the universal curve behavior in the isothermal entropy change unveils the variation in critical exponents around T1 and T2 due to the magnetic inhomogeneity in the alloy. Besides, the electrical transport properties of the metallic alloy denote the maximum magnetoresistance of −10% around T1.