An STM study of the initial oxidation of single-crystalline zirconium surfaces

作者：Bakradze Georgijs; Jeurgens Lars P H^*; Mittemeijer Eric J

来源：Surface Science, 2012, 606(9-10): 846-851.

DOI：10.1016/j.susc.2012.01.026

• Oxidation
• Zirconium oxide
• Scanning tunneling microscopy
• Crystallization
• Surface structure, morphology, roughness and topography
• Thin oxide films

The microstructural development of thin (thickness %26lt;10 nm) oxide layers grown on Zr surfaces by thermal oxidation was investigated by in-vacuo STM and XPS. To this end, single-crystalline Zr(0001) and Zr(10%26lt;(1)over bar%26gt;0) surfaces were prepared under UHV conditions by a cyclic treatment of ion-sputtering and in-vacuo annealing steps and then exposed to dry O-2(g) in the temperature range of 300-450 K (at pO(2) = 1x10(-4) Pa). Oxidation proceeds by the fast formation of a dense arrangement of tiny oxide nuclei, which cover the entire Zr surface. The initial oxide cluster size is about 1.2 +/- 0.1 nm. The transport processes on the oxidizing surface become promoted with increasing temperature and thereby the oxide clusters rearrange into bigger agglomerates with increasing oxidation time. At the same time, a long-range atomic order develops in the oxide overgrowths, as evidenced from the emergence of a bonding/non-bonding fine structure in the resolved oxide-film upper valence band, as measured in-situ by XPS.

• 出版日期2012-5