Positronium decay study of zirconia–silica sol–gels

Positron annihilation lifetime (PAL) and Doppler broadening of annihilation line (DBAL) techniques have been used to investigate the fine-pore structure of the system xZrO2·(1−x)SiO2 (x=4,10 mol%). The samples were prepared by the alkoxide method of sol–gel process. The influences of the ethanol/alkoxide ratio and the heat-treatment on the pore structure have been studied. Pores of two different sizes, R∼3 Å and R∼9–11 Å were measured in the samples studied. It was established that the heat-treatment had greater influence on the defect structure than the ethanol/alkoxide ratio, for both ZrO2 contents.