Abstract

Ferroelectric Pb 0.982-zLA 0.012Δ 0.006Ba z(Zr 0.55Ti 0.45)O 3 (PLZT; z = 0-6 mol%) ceramic compositions were fabricated by a mixed-oxide method. X-ray diffraction studies of sintered ceramics indicate the coexistence of rhombohedral and tetragonal phases in the 5 mol% Ba-doped PLZT composition. Grain growth is inhibited with increasing Ba concentration in the PLZT system as evidenced by scanning electron micrographs. Dielectric constant and dielectric loss as a function of temperature suggest that ε rt and tan 5 are increased up to compositions containing 4 and 5 mol% Ba, respectively. The dielectric maximum (ε Tc) decreased to 4 mol% Ba and gradually increased to 6 mol% Ba, whereas, with increasing Ba concentration in the PLZT system, the Curie temperature (T C) decreased from the composition with no Ba to that with 6 mol% Ba. Relaxor behavior as a function of temperature and frequency was studied over the composition series. As the Ba concentration increased, the coercive field (E c) showed a gradual enhancement. Remanent (P r) and spontaneous (P s) polarizations decreased to the 5 mol% Ba composition. Piezoelectric charge coefficient (d 33), piezoelectric planar coupling coefficient (k p) and piezoelectric thickness coupling coefficient (k t) increased to the 4 mol% Ba composition, which are potential compositions for sensor and actuator applications. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.