The magnetostructural phase transformation and shape memory effect (SME) of Fe-added Ni2MnGa films were investigated. The free-standing films were heat-treated at 1073 K for 3.6 ks and constraint-aged (CA) at various conditions (473 ∼ 723 K, 0 ∼ 14.4 ks) to make the two-way SME. The reversible two-way SME by the temperature change was confirmed through the martensitic transformation (MT) and its reversion. The gradient of strain-temperature curve, the effective recovery strain and the width of thermal hysteresis were dependent on the CA conditions. The magnetic field (MF) induced structural phase transformation was evaluated by an XRD apparatus in high MF up to 5 T. It was confirmed that the martensitic phase was stabilized by the MF. Furthermore, the SME by the MF was observed around MT temperature on cooling process for the CA film. It was concluded that the MF induced SME appeared by the induction of the MT with MF.
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry