Chemical forms of hydroxyls on/in Zirconia: An FT-IR study

Abstract The hydroxyls groups of a heat-treated sample of zirconia powder (1170K, 24 h in O 2 H 2 O ) were studied by FT-IR transmission spectroscopy and compared with those of ‘as-received’ and air annealed zirconia samples. The surface studies were driven ‘in situ’ in a cell allowing heat treatments under either dynamical vacuum (10 −6 hPa) or controlled atmosphere, e.g. deuterium. The hydroxyls on the ‘as-received’ sample were quickly exchanged by OD when, after deuteriation of the sample heat treated in water atmosphere, hydroxyls are still visible. Twenty-five percent of them could not be exchanged even after a 4h extension of the deuteriation process. As a counter-proof in the case of an air treated sample a complete deuteriation of the whole hydroxyls was observed. This difference clearly manifests that, in water annealed zirconia, H species have entered the bulk of the material where they are trapped.