Multi Phase Driven Large Operating Temperature Range Magnetocaloric Effect in In Incorporated HoCo₂ Alloy

The Ho-Co-In alloy was thoroughly studied for its magnetic and magnetocaloric properties, revealing a dual-phase structure comprising cubic HoCo₂ and an unidentifiable phase, with stoichiometry HoCo_1.5In_0.33. At distinct temperatures, T₁ = 123 K and T₂ = 34 K, the alloy showcased ferromagnetic behavior, while transitioning to antiferromagnetic ordering at T₃ = 7 K. The ferromagnetic shifts were determined to be of second-order nature, displaying minimal magnetic hysteresis. The magnetocaloric effect (MCE) was computed using Maxwell’s equations based on isothermal magnetization data. Because of multi-phase nature, the alloy’s multiple magnetic transitions gave rise to twin peaks in the MCE graph, reaching relative cooling power (RCP) value of 595 J/kg for an applied magnetic field change of 0–9 T. Furthermore, the alloy showcased a notable maximum magnetoresistance, registering at -15% around 123 K. These findings shows the alloy’s intricate magnetic behavior and its potential for diverse applications owing to its distinct magnetocaloric and magnetoresistive properties.