Broad First-Order Magnetic Entropy Change Curve in Directionally Solidified Polycrystalline Ni-Co-Mn-In

Authors

F. Chen, Harbin Engineering University
Y. X. Tong, Harbin Engineering University
L. Li, Harbin Engineering University
J. L. Sánchez Llamazares, Instituto Potosino de Investigación Científica y Tecnológica A.C.
C. F. Sánchez-Valdés, Universidad Autónoma de Ciudad Juárez (UACJ)
P. Müllner, Boise State UniversityFollow

Document Type

Article

Publication Date

12-15-2017

Abstract

We present the thermal dependence of the magnetic entropy change ΔS_M(T) across the martensitic transformation for a polycrystalline sample, which was cut from a directionally solidified rod, with a nominal composition Ni₄₂Co₈Mn₃₈In₁₂ grown by the Bridgman-Stockbarger technique. This material combines a first-order martensitic transformation expanded over a very large working temperature range with a large magnetization change of ∼86 A m² kg⁻¹. Accordingly, for a magnetic field change of 5 T (2 T), the coupled magneto-structural transition gives rise to a broad magnetic entropy change curve across the reverse martensitic transformation with a moderate maximum value of 6.8 (3.0) J kg⁻¹ K⁻¹ and a full-width at half-maximum δT_FWHM for the ΔS_M(T) curve of 49 (43) K. Such a broad structural transition may be due to the effect of chemical segregation introduced by the directional solidification which can be enhanced by the non-uniform distribution of second phase particles. Accompanying with such a wide working temperature range, a large refrigerant capacity of 334 J kg⁻¹ was obtained for a field change of 5 T.

Publication Information

Chen, F.; Tong, Y. X.; Li, L.; Sánchez Llamazares, J. L.; Sánchez-Valdés, C. F.; and Müllner, P.. (2017). "Broad First-Order Magnetic Entropy Change Curve in Directionally Solidified Polycrystalline Ni-Co-Mn-In". Journal of Alloys and Compounds, 727, 603-609. https://doi.org/10.1016/j.jallcom.2017.08.118