Ba Modified (Pb, Sr)(Zr, Ti, Nb)O₃ Ceramic System for Dielectric and Ferroelectric Studies

Abstract

In this investigation, (Pb _{0.988 − y} Sr _0.012 Ba _y )(Zr _0.51 Ti _0.47 Nb _0.02 )O ₃ (PSBZTN) where y = 0, 0.5, 1.0 and 1.5 mole% crystalline solid solutions have been fabricated by solid-state reaction method. A ferroelectric phase change occurred from rhombohedral to tetragonal MPB of (Pb_{1 − x − y} Sr _x Ba _y )(Zr_{1 − z − k} Ti _z Nb _k )O₃was observed for y = 0.5 mole% Ba and further Ba increment resulted in strong tetragonality. Microstructure studies reveal that grain growth inhibited while the density profile showed the inter-diffusion between multiple ions and promoted densification. The isovalent substitutions of Ba ^{2 +} and Sr ^{2 +} cations at the Pb site and donor pentavalent Nb ^{5 +} at Zr/Ti site enhanced the dielectric constant (ϵ _RT = 2384) while decreasing the phase transition temperature (T_c). The substitution of 1.5 mole% Ba for Pb evidently increased (P_r = 32.46 μ C/cm ² ) and (P_s = 38.44 μ C/cm²) with relatively decreasing coercive field.

Keywords:

• PZT
• microstructure
• dielectrics
• ferroelectrics

Acknowledgments

The author would like to thank University of Concepcion for their financial assistance extended and Ms. C. Neeladevi for the technical assistance extended during this work.