Microstructure and transformation temperature in alloys with a large magnetocrystalline anisotropy under external fields

Effects of magnetic field on microstructure formation and transformation temperature in diffusionless and diffusional transformations have been investigated. The magnetic field is effective for controlling the microstructure formed in association with both martensitic transformation in ferromagnetic shape memory alloys (Ni2MnGa, Fe–31.2 at.% Pd, Fe3Pt) and diffusional transformation in CoPt. The magnetocrystalline anisotropy is essentially important for understanding the magnetic field dependence of the transformation temperature in Ni2MnGa. Moreover, a new phase appears if a uniaxial stress is applied to the parent and intermediate phases of Ni2MnGa.