Effect of Magnetic Field on Martensitic Transformation Temperature in Ni₂MnGa with Single Variant and Multi-Variant States

Abstract:

We have studied effect of magnetic field on the martensite (10M) to intermediate phase transformation temperature (As) of Ni2MnGa in order to understand the influence of magnetocrystalline anisotropy on the transformation temperature under a magnetic field. In case of the transformation from multi-variant 10M phase to the intermediate phase, As decreases with increasing magnetic field H for H < 0.8 MA/m, and then it increases on further increasing H. On the other hand, in case of the transformation from the single-variant 10M to the intermediate phase, As increases monotonically with increasing H, where the easy axis of the single variant is parallel to the field direction. The difference between the multi-variant and single variant state can be explained by considering the high magnetocrystalline anisotropy of the martensite phase.

• Periodical: Materials Science Forum (Volumes 539-543)
• Pages: 3243-3248
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.539-543.3243
• Online since: March 2007
• Authors: Takashi Fukuda, Jae Hoon Kim, Tomoyuki Kakeshita
• Keywords: Ferromagnetic Shape Memory Alloys (FSMAs), Magnetisation, Martensite, Variants

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