Effects of mechanical activation on the sintering and dielectric properties of oxide-derived PZT

A single phase, nanocrystalline perovskite PZT powder has been successfully derived from a mixture of oxides via a mechanical activation route. Unlike in the conventional solid stale reaction, the perovskite PZT phase was fir st triggered and then progressively formed without passing through the inte rmediate PT and PZ phases with increasing degree of mechanical activation. Similarly, the formation of a single phase PZT of perovskite structure can be completed in a partially activated mixture of oxide powders when heated at an elevated temperature, also without involving PT and PZ as transitiona l phases. Dense PZT (>95% theoretical density) with excellent dielectric pr operties was obtained when the mechanically activated powders are sintered at 1150 degrees C. The relative density and dielectric properties of sinter ed PZT were improved when the formation of perovskite phase is completed by the mechanical activation. (C) 1999 Acta Metallurgica Inc. Published by El sevier Science Ltd. All rights reserved.