Experimental observation of vacancy-assisted martensitic transformation shift in Ni-Fe-Ga alloys
Fecha
2019Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
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10.1103/PhysRevLett.122.165701
Resumen
Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fel7Ga28 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 vaca ...
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Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fel7Ga28 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 L2(1) and B2 phases, which dictate the martensitic transformation temperature and its subsequent evolution. Finally, by electron-positron density functional calculations V-Ni 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. [--]
Materias
Ferromagnetism,
Martensitic phase transition,
Heusler alloy,
Density functional theory,
Differential scanning calorimetry,
Electron-correlation calculations,
Positron annihilation spectroscopy
Editor
American Physical Society
Publicado en
Physical Review Letters, 2019, 122 (16)
Departamento
Universidad Pública de Navarra. Departamento de Ciencias /
Nafarroako Unibertsitate Publikoa. Zientziak Saila /
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. Institute for Advanced Materials - INAMAT
Versión del editor
Entidades Financiadoras
This work is supported by the Basque Government Grant No. IT-1005-16 and by the Spanish Ministry of Economy and Competitiveness under the Projects No. MAT2015-65165-C2-R (MINECO/FEDER) and No. MAT2014-56116-C4-1-R (AEI/FEDER). I. U. acknowledges the Basque Government Grant No. PRE-2014-214.