Effect of oxygen activity on chromium segregation in Cr-doped TiO single crystal.

The present work determined the effect of chromium segregation on surface and near-surface composition of Cr-doped TiO (0.05 at.% Cr) after annealing in oxidising and strongly reducing environments at 1,073 and 1,273 K. The segregation-induced depth profiles were determined by secondary ion mass spectrometry (SIMS). It was observed that annealing in oxidising conditions [p(O) = 10 Pa] and reducing conditions [10 Pa > p(O) > 10 Pa] results in an enrichment and depletion of the surface layer in chromium, respectively. The observed effects may be used for tailoring the surface and near-surface composition in order to impose desired properties. [ABSTRACT FROM AUTHOR]