Exploration of room-temperature magnetocaloric effect in nanogranular Ni-Cr thin films

From multicomponent high-entropy alloys (AlCoCrFeNi) through ternary alloys (CrFeNi) to binary (NiCr) alloys, Cr doping plays a critical role in altering the magnetocaloric properties of the resultant alloys. Magnetocaloric effect (MCE) of Ni100-xCrx (x = 5, 10, 15 at.%) nanogranular thin films were investigated by varying Cr concentration, which demonstrate near room-temperature magnetic entropy change (- delta S-M = 0.08 J/kg K) and relative cooling power (RCP = 25 J/kg) at 10 at.% Cr. The MCE properties are well predicted using a phenomenological model based on magnetization as a function of temperature, and they correlate well with experimentally measured magnetic isotherms.