Magnetic-field-induced metamagnetic reverse martensitic transformation and magnetocaloric effect in all-d-metal Ni36.0Co14.0Mn35.7Ti14.3 alloy ribbons

The microstructure, crystalline structure, martensitic transformation, and magnetocaloric effect are systematically studied in all-d-metal Ni36.0Co14.0Mn35.7Ti14.3 alloy ribbons fabricated by melt-spinning technique. Five-layer modulated martensite (5 M) and B2 austenite coexist in both melt-spun and annealed ribbons. Interestingly, all ribbons show a staircase-like magnetic-field-induced metamagnetic reverse martensitic transformation. Accordingly, large magnetocaloric effect near room temperature is obtained, including large magnetic entropy changes of 10 and 13 Jkg−1K−1 and large effective refrigerant capacity of 62 and 63 Jkg-1 under the field change of Δμ0H = 0–2 T, for melt-spun and annealed ribbons, respectively, making the all-d-metal Ni-Mn-based alloy ribbons promising for room temperature magnetic refrigeration.