Magnetic properties and phase diagram of Ni50Mn50−xGax ferromagnetic shape memory alloys

We present the magnetic properties and the magnetic phase diagram of Ni50Mn50−xGax ferromagnetic shape memory alloys across a wide concentration range. Martensitic transformation, intermediate transformation, B2–L21 order–disorder transformation, Néel and Curie temperatures are determined for the prepared samples. The martensitic transformation temperature decreases with increasing Ga concentration and bends two times when crossing the Curie temperature and the intermediate-phase transformation temperature. Spontaneous magnetization and its composition dependence were also investigated. Composition dependence of the transformation temperatures and the spontaneous magnetization in the martensite phase of Ni50Mn50−xGax are compared with those of Ni50Mn50−xInx and Ni50Mn50−xSnx, revealing a similarity in the NiMn-based alloy systems.