Proton-irradiation-induced structural and magnetic property changes in Ni–Mn–Ga high-temperature shape memory films
| Autor: | Zhai-Ping Yang, Zhiyong Gao, Wei Cai |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Austenite Materials science Proton Mechanical Engineering Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Fluence Amorphous solid Differential scanning calorimetry Nuclear magnetic resonance Mechanics of Materials Martensite 0103 physical sciences Curie temperature General Materials Science Irradiation 0210 nano-technology |
| Zdroj: | Materials Science and Engineering: B. 223:76-83 |
| ISSN: | 0921-5107 |
| DOI: | 10.1016/j.mseb.2017.06.004 |
| Popis: | Ni51.90Mn28.86Ga19.24 alloy films were irradiated by 120 keV protons at different fluences to investigate the effect of irradiation on their crystal structure, phase-transition temperature, and magnetic properties. The results show not only that a nanoscale amorphous layer may have been induced on the surface, but also that non-modulated (NM) martensite was produced. Moreover, differential scanning calorimetry peaks of the martensitic and austenitic transition temperatures are shifted to higher temperatures after irradiation; in particular, two endothermic and two exothermic peaks were observed for a proton fluence of 2.0 × 1016/cm2. Further, the formation of NM martensite could produce an extra shoulder on the M–T curves of the irradiated films. Regarding the magnetic properties, a gradual decrease in the Curie temperature TC can be caused by irradiation at a higher proton fluence. The changes in the saturation magnetization Ms with the proton fluence seem to be related to the reduction in TC. |
| Databáze: | OpenAIRE |
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