PAC characterization of Gd and Y doped nanostructured zirconia solid solutions.

CARACOCHE M. C., MARTÍNEZ J. A., PASQUEVICH A. F., D’JURADO E. AND BOULC´H F.

PHYSICA B - CONDENSED MATTER

Año: 2006 vol. B389 p. 98 - 102

0921-4526

A perturbed angular correlations (PAC) study as a function of temperature has been carried out on spray pyrolysis-derived powders and compacts of 3.5 mol% Y2O3-ZrO2 and 2 mol% Gd2O3-ZrO2 nanostructured tetragonal zirconias. The powders undergo the ordinary thermal transformation between the two known defective t´-form and regular t-tetragonal forms and also a partial and irreversible change to an ordered cubic configuration. The dynamical nature of the t´-form leads to an activation energy of about 0.15 eV for the oxygen vacancies movement. The as-obtained compacts do not exhibit any known cubic nanostructure but some additional contributions. In both of them a hyperfine components assigned to the otrthorhombic phase is determined. In the smaller cation Y doped ceramic a small amount of monoclinic phase reflects an incomplete stabilization.