Crystal Structure of Ni50Mn29Ga21Tb1.2 Magnetic Shape Memory Alloy at Room Temperature

Martensitic transformations, martensitic structures and substructures of Ni 50 Mn 29 Ga 21 Tb 1.2 shape memory alloy were studied by DTA, X-ray diffraction and electron diffraction. The results show that the mainly phase at room temperature has body-centred tetragonal structure with the lattice parameters: a=b=0.60 nm, c=0.5546 nm; and has body-centred monoclinic with lattice parameters: a=0.616 nm, b=0.581 nm, c=0.553 nm, β=90.8° in some tiny area. The substructures of Ni50Mn29Ga21Tb1.2 at room temperature are twin.