J. Phys. IV France 7 (1997) C2-1209-C2-1210
Study of the Chemical State and Local Structure of Zirconium in Polycrystalline α-Alumina by X-Ray Absorption Spectroscopy and STEM Analysis of Thin FoilsM.K. Loudjani1 and R. Cortès2
1 Laboratoire de Métallurgie Structurale, URA 1107 du CNRS, Bât. 413, 91405 Orsay, France
2 Laboratoire de Physique des Liquides et Électrochimie, CNRS, UPR15, Université Pierre et Marie Curie, 75230 Paris cedex 05, France
The chemical state and local structure around zirconium in doped α-polycrystalline alumina (300 wt. ppm %. ZrO2) was studied by Extended X-Ray Absorption Fine Structure (EXAFS) measurements at zirconium K-edge energy and by STEM analysis on thin foils. It appared that most of the zirconium is located in grain boundaries as nanocrystalline tetragonal zirconia particles. This allotropic tetragonal zirconia form is stabilised at room temperature because of the important contribution of the surface free energy.
© EDP Sciences 1997