Magnetocaloric effect and engineering trade-offs in Gd-based rare earth binary alloys: a comparative analysis

This study computationally investigates Gd_xR_(1-x) binary alloys (R = Tb, Dy, Ho, Er, Tm) to develop magnetocaloric materials that outperform pure Gadolinium (Gd) for room-temperature magnetic refrigeration. Using the Weiss-Debye-Sommerfeld model, performance was assessed via energetic metrics (ΔT_ad, ΔS_T, RCP) and practical engineering indicators based on mass, volume, cost, and abundance. Among the pure elements, Ho was the top performer. Critically, the alloys Gd₀.₆Ho₀.₄ and Gd₀.₆Dy₀.₄ were identified as the most effective compositions at 2 T, with Gd₀.₆Ho₀.₄ enhancing the mass- and volume-based Relative Cooling Power by 12.5% and 18%, respectively, over pure Gd. These findings identify specific, high-performance candidates for next-generation magnetic cooling technologies.