Short range investigation of sub-micron zirconia particles

CARACOCHE M. C.; MARTÍNEZ J. A.; RIVAS P. C.; BONDIOLI F.; CANNILLO V.; FERRARI A. M.

Puerto Iguazú, Argentina

Simposio; XIX Latin American Symposium on Solid State Physics; 2008

The Perturbed Angular Correlations technique was used to determine the nanoconfigurations around Zirconium ions and their thermal behavior in two powder samples, each one consisting of non-aggregated, sub-micron zirconia spherical particles of unlike sizes. Three residues containing- Zr surroundings were determined for the non-crystalline starting particles, which were interpreted under the assumption that a certain chemical sequence during synthesis had taken place. While the one made up mainly by hydroxyl groups was common to both samples, the two involving mainly organic residues were particle size dependent. Upon crystallization, both samples showed the stabilization of the t’- and t- tetragonal forms and the Xc-cubic form. Nevertheless, the corresponding amounts and temperatures of appearance were different. On heating, the structure of the smaller particles became gradually monoclinic achieving total degradation upon the subsequent cooling to RT. Instead, probably due to their lower specific surface area that favors the permanence of the oxygen defective t’- form, the bigger particles remained stabilized up to 1000C and became half monoclinic during cooling.