Abstract
The effect of heat treatment on the properties of Ni-Mn-Ga films such as chemical composition, crystal structure, microstructure and transformation temperature were investigated with respect to various sputtering conditions. Ni-Mn-Ga films were deposited on a poly-vinyl alcohol substrate with a radio-frequency magnetron sputtering apparatus using Ni50Mn25Ga25 and Ni52Mn24Ga24 targets. After separating from the substrates, the films were annealed at temperatures between 873 and 1273 K for 3.6 ks. The chemical composition of the films depended on the sputtering power, but there was no dependence on the heat treatment temperature. Each deposited film had a columnar grain structure. After the heat treatment, the width of the columnar grains increased and then became indistinct with increasing heat treatment temperature. The martensitic transformation temperature increased with increasing nickel content of the films, while the Curie temperature decreased. The film heat-treated at 1073 K showed a two-way shape memory effect through the martensitic transformation and its reversion.
| Original language | English |
|---|---|
| Pages (from-to) | 49-59 |
| Number of pages | 11 |
| Journal | International Journal of Applied Electromagnetics and Mechanics |
| Volume | 12 |
| Issue number | 1-2 |
| Publication status | Published - 2000 Dec 1 |
Keywords
- Crystal structure
- Martensitic transformation
- Microstructure
- Nickel-manganese-gallium
- Shape memory effect
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Mechanics of Materials
- Computational Mechanics
- Physics and Astronomy (miscellaneous)