NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

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
Pub Type
Journals

Keywords

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

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 October 9, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created August 20, 2016, Updated October 12, 2021
Was this page helpful?