Giant enhancement of the magnetocaloric response in Ni–Co–Mn–Ti by rapid solidification

Magnetocaloric refrigeration is a solid-state cooling approach that promises high energy efficiency and low environmental impact. It remains uncompetitive with conventional vapor-compression technologies due to lack of high-performing materials that exhibit large magnetocaloric effects in low magnetic fields. Here we report a game-changing enhancement of the magnetocaloric response in a transition-metal-based Ni–Co–Mn–Ti. Mechanically and chemically stable rapidly solidified ribbons exhibit magnetic entropy changes as high as ∼27 J⋅kg⁻¹K⁻¹ for a moderate field change of 2 T, comparable to or larger than the best known materials for near-room temperature applications. The ribbons can be easily manufactured in large quantities and the transition temperature can be adjusted by varying Co concentration.