Characterization of densified fully stabilized nanometric zirconia by positron annihilation spectroscopy

Fully-stabilized nanometric zirconia samples with varying degrees of porosity and grain sizes were analyzed using the coincidence Doppler broadening mode of the positron annihilation spectroscopy (PAS). A decrease in the low momentum fraction was observed and coincided with a decrease in porosity. In addition to pores, it is proposed that defects in the negatively charges grain boundary space region act as positron trapping centers; their effectiveness decreases with an increase in grain size. It is shown that PAS is sensitive to small grain size differences within the nanometric regime in these oxide materials