Reactions in TiO2/Ti3Al and TiO2/TiAl bilayers: application of target-factor analysis in Auger electron spectroscopy

Bilayers of TiO2/Ti3Al and TiO2/TiAl were heated up to 973 K, The resulting concentration-depth profiles were determined using Auger electron spectros copy in combination with ion sputtering. By applying target-factor analysis it was possible to distinguish between different states of chemical bondin g of the elements analysed. In both TiO2/Ti3Al and TiO2/TiAl heating causes decomposition of titanium dioxide at the bilayer interface, as revealed by the associated oxygen diffusion into the metallic layer. In a certain dept h range near to the original bilayer, interface oxygen is bonded to both Ti and Al. In the original Ti3Al layer oxygen dissolves homogeneously, wherea s Al2O3 was formed in the original TiAl layer, particularly in the central region. Copyright (C) 2000 John Wiley & Sons, Ltd.