Experimental observation of vacancy assisted martensitic transformation shift in Ni-Fe-Ga alloys
[EN] Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fe17Ga28 alloy. The evolution of vacancies assisting the ordering enables shifts of the martensitic tr...
| Autores: | , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/63364 |
| Acceso en línea: | http://hdl.handle.net/10810/63364 |
| Access Level: | acceso abierto |
| Palabra clave: | vacancies heusler alloys density functional theory ferromagnetism positron annihilation spectroscopy martensitic phase transition |
| Sumario: | [EN] Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fe17Ga28 alloy. The evolution of vacancies assisting the ordering enables shifts of the martensitic transformation up to 50 K. Our results confirm the role that both vacancy concentration and different vacancy dynamics play in samples quenched from the L21 and B2 phases, which dictate the martensitic transformation temperature and its subsequent evolution. Finally, by electron-positron density functional calculations VNi is identified as the most probable vacancy present in Ni55Fe17Ga28. This work evidences the capability of vacancies for the fine-tuning of the martensitic transformation temperature, paving the way for defect engineering of multifunctional properties. |
|---|