Successful synthesis of nanocrystalline perovskite lead scandium tantalate,
PbSc0.5Ta0.5O3, was achieved via a novel one-step mechanical activation ro
ute. The as-formed PST exhibits a disordered structure and nanocrystalline
domains of similar to 8nm. Sintered ceramics made from these powders retain
long-range disordered perovskite structure up to 1200 degreesC and a diele
ctric constant of similar to 23,000 is obtained. Sintering above this tempe
rature results in the formation of undesirable pyrochlore phases that degra
des dielectric properties. (C) 2001 Acta Materialia Inc. Published by Elsev
ier Science Ltd. All rights reserved.