An investigation of structures of thermal and anodic tantalum oxide films

2020-03-22 10:03:56

structure films ray oxide Ta2O5

责任者: Maeng, S.;Axe, L.;Tyson, T.;Jiang, A. 单位: Dept. of Civil & Environ. Eng., New Jersey Inst. of Technol., Newark, NJ, USA 来源出处: Journal of the Electrochemical Society(J. Electrochem. Soc. (USA)),2005/02/,152(2):60-4 摘要: Tantalum oxide films produced from anodic oxidation and thermal oxidation at 400 and 800°C have been investigated with respect to long- and short-range structure by X-ray diffraction and X-ray absorption spectroscopy, respectively. Films formed at 800°C show orthorhombic structure (β-Ta2O5) with greater disorder compared to the β-Ta2O5 powder reference, where six O atoms were observed at an average radial distances of 1.957±0.014 (Ta2O5 powder) and 1.971±0.007 Å (800°C Ta oxide film). Lower temperature films consist primarily of metastable TaOx (Ta2O) and appear to be relatively stable for extended times of treatment with a first shell not unlike that of β-Ta2O5, based on a linear combination analysis. Furthermore, using a linear combination of β-Ta2O5 and α-Ta metal, the amorphous anodic oxide films studied as a function of thickness were observed to exhibit a relatively ordered local structure consistent with the high-temperature (i.e., 800°C) phase. This work demonstrates that the nanoscale oxide films formed on tantalum exhibit an ordered local structure, reflecting the very compact nature that enhances its corrosion resistance 关键词: amorphous state;anodisation;corrosion resistance;Fourier transform spectra;long-range order;noncrystalline structure;oxidation;short-range order;tantalum compounds;thin films;X-ray absorption spectra;X-ray diffraction;anodic tantalum oxide films;anodic oxidation;thermal oxidation;short range structure;X-ray diffraction;X-ray absorption spectroscopy;orthorhombic structure;Ta2O5 powder;linear combination analysis;amorphous anodic oxide films;high temperature phase;nanoscale oxide films;ordered local structure;corrosion resistance;Fourier transform spectra;400 degC;800 degC;Ta2O5