XPS investigations of the interactions of hydrogen with thin films of zirconium oxide I. Hydrogen treatments on a 10 Å thick film

• Published in: Applied surface science Vol. 89; no. 3; pp. 255 - 261
• Main Authors: Wong, P.C., Li, Y.S., Zhou, M.Y., Mitchell, K.A.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 1995; Elsevier Science
• Subjects: Adsorbed layers and thin films; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Diffusion; interface formation; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; General and physical chemistry; Photoemission and photoelectron spectra; Physics; Solid surfaces and solid-solid interfaces; Solid-gas interface; Surface physical chemistry; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Surface reaction; Heat treatment; Zirconium oxide; Solid solid interface; Transition element compounds; Photoelectron spectrometry; X ray; Experimental study; Hydrogenation; Inorganic compound; Thin film
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/0169-4332(95)00031-3

Interactions of hydrogen with the interface formed between ZrO 2 and zirconium suboxide (ZrO x , x < 2) were studied on a 10 Å zirconium oxide film prepared on gold foil for X-ray photoelectron spectroscopy (XPS) analysis. This film was subject to a set of sequential treatments. Reaction with H 2 gas at 2 mbar pressure and room temperature indicates that the ZrO 2 ZrO x interface appeared to undergo a redox-type reaction and convert to a new ZrO 2 ZrO y ( x< y<2) film. Heating this structure at 300°C in a 10 −9 mbar vacuum (residual gas dominantly H 2O) resulted in more ZrO 2 in the outer region and less ZrO y in the subsurface. By contrast, when this film was treated with a hydrogen plasma, XPS showed enhanced formation of OH groups and complete conversion to the ZrO 2-like form. On heating to 300°C, this uniform film regenerates the ZrO 2 ZrO y interface structure, apparently with desorption of H 2O.