Stabilization of perovskite phase and dielectric properties of 0.95PZN-0.05BT derived from mechanical activation

0.95Pb(Zn1/3Nb2/3)O-3-0.05BaTiO(3) (0.95PZN-0.05BT) of perovskite structure has been successfully synthesized by mechanically activating a powder mixt ure of PbO, Nb2O5, ZnO, BaO, and TiO2. Nanosized 0.95PZN-0.05BT perovskite particles were triggered to form in the powder mixture mechanically activat ed for 20 h. The resulting perovskite phase undergoes a decomposition react ion to form pyrochlore phase with increasing heat treatment temperature ove r the range of 450 to 700 degrees C. Further increasing the heat treatment temperatures above 700 degrees C results in a recovery of the perovskite ph ase as a consequence of the stabilization of PZN by BaTiO3. Sintering at 11 00 degrees C for 1 h led to similar to 94% perovskite phase and a sintered density of similar to 96% theoretical in 0.95PZN-0.05BT. Sintered 0.95PZN-0 .05BT exhibits a peak dielectric constant of 14000 and a dielectric loss of 0.02 at the Curie temperature of 98 degrees C when measured at a frequency of 100 Hz. (C) 2000 Elsevier Science S.A. All rights reserved.