Martensitic Transformation and Electronic Structures of the Shape Memory Alloy Ni₂(Pd_0.17Mn_0.83)Ga

抄録

The alloy Ni₂(Pd_0.16Mn_0.84)Ga is a ferromagnetic shape memory alloy that has coexistent orthorhombic and monoclinic structures at low temperatures and a cubic structure at high temperatures. To study the characteristic properties, the electronic structures were calculated for the three structures. The total energy and the band energy suggest that the orthorhombic and monoclinic structures may more stable than the cubic structure; that is, they may become the martensitic structure. It is also predicted that the monoclinic structure is the most stable and that the orthorhombic structure may be metastable. The Pd atoms play an important role in stabilizing the monoclinic structure.