On the amorphous and nanocrystalline Zr–Cu and Zr–Ti co-sputtered thin films

• Published in: Journal of alloys and compounds 2009-08, Vol.483 (1), p.337-340
• Main Authors: Chen, C.J., Huang, J.C., Chou, H.S., Lai, Y.H., Chang, L.W., Du, X.H., Chu, J.P., Nieh, T.G.
• Format: Article
• Language: English
• Subjects: Amorphous materials; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Intermetallics; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Scanning and transmission electron microscopy; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.07.188

In the current study, we examined and compared the mixing and vitrification behavior of the Zr–Cu and Zr–Ti binary systems in the form of co-sputtered thin films with or without post-annealing. The co-sputtered Zr–Cu films are all amorphous under various co-sputtering conditions, suggesting the high vitrification tendency. The amorphous Zr–Cu thin film will start to crystallize into nano-crystalline Zr 2Cu and Zr 7Cu 10 phases upon long exposure at temperatures above 350 °C. On the other hand, it is difficult to form amorphous film with the Zr–Ti system, except at a low sputtering power of 30–50 W. The low powers enable the co-sputtered Zr–Ti thin film to exhibit the diffuse hump in the X-ray diffraction. Examination by high resolution transmission electron microscopy reveals numerous fine nano-crystalline phases around 2 nm in the amorphous matrix. Upon exposure at 700 °C, the Zr–Ti films transform into crystalline hexagonal close-packed α and body-centered cubic β phases.