Effect of niobium addition on the martensitic transformation and magnetocaloric effect in low hysteresis NiCoMnSn magnetic shape memory alloys

Journal Article · Mon Dec 08 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4903494· OSTI ID:22395466

Emre, Baris ^[1]; Bruno, Nickolaus M. ^[2]; Yuce Emre, Suheyla ^[3]; Karaman, Ibrahim ^[2]

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1. Department of Engineering Physics, Ankara University, 06100 Ankara (Turkey)
2. Department of Mechanical Engineering, Texas A and M University, College Station, Texas 77843 (United States)
3. Department of Physics, Ondokuz Mayis University, 55139 Samsun (Turkey)

The effect of Nb substitution for Ni in Ni{sub 45}Co{sub 5}Mn{sub 40}Sn{sub 10} magnetic shape memory alloys on their magnetic properties, martensitic transformation characteristics, transformation hysteresis, and magnetocaloric properties was studied using wavelength-dispersive X-ray spectroscopy, differential scanning calorimetry, and the temperature and field dependence of the magnetization. Ni{sub 45}Co{sub 5}Mn{sub 40}Sn{sub 10} alloy has a very low transformation hysteresis; however, the martensitic transformation temperatures are notably above room temperature, which is not desirable for magnetic refrigeration applications. In this study, small quantities of Nb substitution were shown to drastically shift the transformation temperatures to lower temperatures, at a rate of 68 K/at. % Nb, which is needed for household refrigeration. The austenite Curie temperature also decreased with increasing Nb content. However, a decrease in the latent heat of the martensitic transition was observed, which negatively affects the magnetic field-induced adiabatic temperature change capability. Still, the relatively large transformation entropy and the low transformation hysteresis make the Nb-doped Ni{sub 45}Co{sub 5}Mn{sub 40}Sn{sub 10} alloys potential candidates for solid state refrigeration near room temperature.

• OSTI ID: 22395466
• Journal Information: Applied Physics Letters, Vol. 105, Issue 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AUSTENITE
CALORIMETRY
COBALT ALLOYS
CURIE POINT
DIFFERENTIAL THERMAL ANALYSIS
DOPED MATERIALS
ENTROPY
HYSTERESIS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE BASE ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ADDITIONS
PHASE TRANSFORMATIONS
REFRIGERATION
SHAPE MEMORY EFFECT
TEMPERATURE RANGE 0273-0400 K
X-RAY SPECTROSCOPY