Effect of anisotropy on microellipsometry in the TiTiO2 system
Abstract Electrochemical in situ ellipsometry with a focused laser beam (microellipsometry) is used to determine properties of oxide layers on single grains of Ti. The data for δ and Ψ differ from grain and also a strong dependence on the sample rotation around the surface normal occurs. This is due to the anisotropy of the Ti TiO 2 system. The measurements deliver information about the epitaxy of oxide layer formation and the orientation of the substratum's optical axis, which is proved by measurements on well-oriented single crystals. A method for data interpretation is presented which possibly allows the determination of oxide growth rates on Ti single grains despite their anisotropy. Measurements with microreflection spectroscopy and a photocurrent laser-scanning method confirm the microellipsometric results.