| Abstract
| - EXAFS spectroscopy performed on nanocrystalline anatase TiO2 powder and a nanocrystalline anatase ceramic gives clear indication for Zn segregation, but Nb segregation is not observed. This behavior is compatible with a space charge segregation model, assuming a positively charged interface core, due to easy interface reduction.
- Segregation of an acceptor (Zn) and a donor dopant (Nb) in nanocrystalline anatase wasstudied by EXAFS spectroscopy. Different dopant concentrations between 0.1 and 1 at. %were investigated, and similar results were found for nanocrystalline powders and nanocrystalline ceramics made by hot-pressing the powders. Niobium did not segregate whateverthe concentration, whereas zinc segregation was found above 0.1 at. %. These results canbe interpreted based on defect thermodynamics, in the framework of a space chargesegregation model.
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