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Effect of Grain Constraint on the Field Requirements for Magnetocaloric Effect in Ni(sub45)Co(Sub5)Mn(Sub40)Sn(sub10) Melt-Spun Ribbons

Published

Author(s)

N. M. Bruno, Y. J. Huang, Cindi L. Dennis, J. G. Li, Robert D. Shull, J. H. Ross Jr., Y. I. Chumlyakov, I. Karaman

Abstract

The influence of grain constraint on the magnetic field levels required to complete the isothermal martensitic transformation in magnetic shape memory alloys has been demonstrated for a NiCoMnSn alloy and the magnetocaloric performance of an optimally heat treated alloy was quantified. Ni(sub45)Co(Subx)Mn(Sub45-x)Sn(sub10) melt spun ribbons with x=2, 4, 5, and 6 were characterized, and the Co(Sub5) composition was determined to exhibit the lowest transformation thermal hysteresis and transformation temperature range from austenite to martensite, as well as a large latent heat of transformation (45 J kg(superscript-1)K(superscript-1). For this composition, it was found that increasing the grain size to thickness ration of the ribbons from 0.2 to 1.2, through select heat treatments, resulted in a decrease of the magnetic field required to induce the martensitic transformation by about 3 T due to the corresponding reduction in the martensitic transformation temperature range. This decrease in the field requirement ultimately led to a larger magnetocaloric entropy change achieved under relatively smaller magnetic field levels. The giant inverse magnetocaloric effect of the optimized alloy was measured and showed that up to 25 J kg(superscript-1) K(superscript-1) was generated by driving the martensitic transition with magnetic fields up to 7 T.
Citation
Journal of Applied Physics

Keywords

Magnetocaloric effect, Magnetic shape memory alloys, Martensitic Transformation, Grain size, Melt-spun ribbons

Citation

Bruno, N. , Huang, Y. , Dennis, C. , Li, J. , Shull, R. , Ross Jr., J. , Chumlyakov, Y. and Karaman, I. (2016), Effect of Grain Constraint on the Field Requirements for Magnetocaloric Effect in Ni(sub45)Co(Sub5)Mn(Sub40)Sn(sub10) Melt-Spun Ribbons, Journal of Applied Physics (Accessed April 24, 2024)
Created August 20, 2016, Updated October 12, 2021