Processing of Pb(Zn_1/3Nb_2/3)O₃ ceramics at high pressures

Lead zinc niobate (PZN) with 1 mole% of BaTiO₃ (BT) and pure PZN, both of pyrochlore structure were synthesized by solid state and sol-gel routes respectively. The pyrochlore ceramics were subjected to high pressures (20-35 Kbars) to convert them to perovskite phases. About 80% of perovskite phase was formed from sol-gel derived PZN ceramics while only about 53% perovskite resulted from conventionally processed PZN with 1 mole% BaTiO₃ additive at 20 Kbar, 2 hr. A maximum dielectric constant value of 11200 was obtained at 1 kHz for the PZN ceramics processed with 20 Kbar pressure.