Abstract
Pb-rich second phases in perovskite-structured Pb(Sc1/2Ta1/2)O3 (PST) ferroelectric ceramic relaxors have been investigated using transmission electron miscroscopy. The second phases were observed to exhibit a range of morphologies which included: spheroids, plate-like precipitates and intergranular films. It is proposed that excess PbO which is used as an aid to sintering becomes entrapped within the perovskite matrix, thereby causing Pb-enriched phases.