Ferromagnetic shape memory alloy Ni₂MnGa films

Abstract
Heusler type Ni₂MnGa is a ferromagnetic shape memory alloy. Martensitic transformation occurs within the ferromagnetic temperature range. Ni₂MnGa films were fabricated by the melt spinning method and the sputtering method. The physical properties, such as transformation temperatures and magnetic behaviors, of these films was studied. These films had good crystallinity with preferred orientation and showed the crystal structure as same as bulk specimen. Rapidly solidified Ni₂MnGa films made by the single roll melt spinning method have 20 µm in thickness and 1mm in width. Sputtered Ni₂MnGa films were made by using a high frequency magnetron sputtering apparatus. The thickness of the film was 5 µm. The films which were deposited on the poly-vinyl alcohol substrate showed shape memory effect.