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Diffusion evaluation of Cu in NiTi Bi-layer thin film interface

Mohri, Maryam ; Nili-Ahmadabadi, Mahmoud ; Flege, Stefan (2014)
Diffusion evaluation of Cu in NiTi Bi-layer thin film interface.
In: Journal of Alloys and Compounds, 594
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

NiTi alloys are shape memory alloys (SMAs) which combine two very unique properties, shape memory effect and super-elasticity. These properties depend strongly on the composition and structure. In this research volume diffusion of Cu in bulk Ni50.8Ti49.2 alloy with B2 ordered structure has been measured and diffusion phenomenon on a bi-layer Ni-Ti thin film was also studied. The penetration profiles were determined by two techniques: secondary ion mass spectroscopy (SIMS) and energy dispersive X-ray analysis (EDS). Cu diffusivity in NiTi-Ni rich bulk was found to follow linear Arrhenius dependencies with the pre-exponential factor of 5.8 ± 1 x 10^-14 m2/s and the activation energy of 40 ± 4 kJ/mol. Anti-site defect diffusion mechanism is suggested to provide diffusion of copper in NiTi alloy. The diffusion coefficient of Cu in Ni-Ti Ni-rich was used to estimate the gradient composition in the bi-layer thin film (Ni-rich/NiTiCu) after annealing. The bi-layer thin film was deposited on Si (1 1 1) using DC magnetron sputtering and annealed at 773 K for 1 h. The crystallization temperature and microstructure of the thin film were characterized using differential scanning calorimeter (DSC) and X-ray diffractometer (GIXRD). The results depicted that estimation of the concentration gradient in the bi-layer thin film using the diffusion equation obtained from the NiTi bulk samples shows good agreement with the measured concentration gradient in the bi-layer.

Typ des Eintrags: Artikel
Erschienen: 2014
Autor(en): Mohri, Maryam ; Nili-Ahmadabadi, Mahmoud ; Flege, Stefan
Art des Eintrags: Bibliographie
Titel: Diffusion evaluation of Cu in NiTi Bi-layer thin film interface
Sprache: Englisch
Publikationsjahr: 5 Mai 2014
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Journal of Alloys and Compounds
Jahrgang/Volume einer Zeitschrift: 594
URL / URN: http://www.sciencedirect.com/science/article/pii/S0925838814...
Kurzbeschreibung (Abstract):

NiTi alloys are shape memory alloys (SMAs) which combine two very unique properties, shape memory effect and super-elasticity. These properties depend strongly on the composition and structure. In this research volume diffusion of Cu in bulk Ni50.8Ti49.2 alloy with B2 ordered structure has been measured and diffusion phenomenon on a bi-layer Ni-Ti thin film was also studied. The penetration profiles were determined by two techniques: secondary ion mass spectroscopy (SIMS) and energy dispersive X-ray analysis (EDS). Cu diffusivity in NiTi-Ni rich bulk was found to follow linear Arrhenius dependencies with the pre-exponential factor of 5.8 ± 1 x 10^-14 m2/s and the activation energy of 40 ± 4 kJ/mol. Anti-site defect diffusion mechanism is suggested to provide diffusion of copper in NiTi alloy. The diffusion coefficient of Cu in Ni-Ti Ni-rich was used to estimate the gradient composition in the bi-layer thin film (Ni-rich/NiTiCu) after annealing. The bi-layer thin film was deposited on Si (1 1 1) using DC magnetron sputtering and annealed at 773 K for 1 h. The crystallization temperature and microstructure of the thin film were characterized using differential scanning calorimeter (DSC) and X-ray diffractometer (GIXRD). The results depicted that estimation of the concentration gradient in the bi-layer thin film using the diffusion equation obtained from the NiTi bulk samples shows good agreement with the measured concentration gradient in the bi-layer.

Freie Schlagworte: Compositional gradient, Cu, Diffusion, NiTi thin films
Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialanalytik
11 Fachbereich Material- und Geowissenschaften
Hinterlegungsdatum: 06 Mär 2014 16:22
Letzte Änderung: 06 Mär 2014 16:22
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