X-ray diffraction mapping in synchrotron experiments shows a fiber texture in microcrystalline Ni-Mn-Ga films deposited and annealed on an alumina ceramic substrate. The texture scans do not reveal a significant in-plane orientation preference. Resistivity curves show that the onset of martensitic transformation depends non-monotonically on the film thickness. This dependence is correlated with the behavior of texture as a function of film thickness. A magnetic field-induced actuation is obtained for a film/substrate thickness ratio of 1/30.
- Martensitic phase transformation
- Ni-Mn-Ga Heusler alloy
- Thin films