Entropy Change during Martensitic Transformation in Ni50−xCoxMn50−yAly Metamagnetic Shape Memory Alloys

Xiao Xu; Wataru Ito; Takeshi Kanomata; Ryosuke Kainuma

doi:10.3390/e16031808

Entropy (Mar 2014)

Entropy Change during Martensitic Transformation in Ni50−xCoxMn50−yAly Metamagnetic Shape Memory Alloys

Xiao Xu,
Wataru Ito,
Takeshi Kanomata,
Ryosuke Kainuma

Affiliations

Xiao Xu: Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
Wataru Ito: Department of Materials and Environmental Engineering, Sendai National College of Technology, Natori 981-1239, Japan
Takeshi Kanomata: Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
Ryosuke Kainuma: Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan

DOI: https://doi.org/10.3390/e16031808
Journal volume & issue: Vol. 16, no. 3
pp. 1808 – 1818

Abstract

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Specific heat was systematically measured by the heat flow method in Ni50-xCoxMn50-yAly metamagnetic shape memory alloys near the martensitic transformation temperatures. Martensitic transformation and ferromagnetic–paramagnetic transition for the parent phase were directly observed via the specific heat measurements. On the basis of the experimental results, the entropy change was estimated and it was found to show an abrupt decrease below the Curie temperature. The results were found to be consistent with those of earlier studies on Ni-Co-Mn-Al alloys.

Published in Entropy

ISSN: 1099-4300 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Astronomy: Astrophysics; Science: Physics
Website: http://www.mdpi.com/journal/entropy

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