Phase stability, dielectric and piezoelectric properties of the Pb(Sc1/2Nb1/2)O3-Pb (Zn1/3Nb2/3)O3-Pb TiO3 ternary ceramic materials

The crystal structure and electrical properties of xPb(Sc1/2Nb1/2)O3-yPb(Zn1/3 Nb2/3)O 3-zPbTiO 3 (PSZNT 100x/100y/100z) ternary ceramic materials have been systematically investigated. Stable perovskite-phase ceramics are obtained with less than 20 mol% of Pb(Zn1/3Nb2/3)O3 and more than 50 mol% of PbTiO3. Piezoelectric properties were found to peak at PSZNT 31/40/29, where the electromechanical coupling factor kp is 60%. The dielectric constant is 2,020, and Curie temperature (Tc) is 222 °C. An interesting property of PSZNT is a nonlinear Tc change in terms of the composition. Tc decreases with increasing PbTiO3 content in the range 0.3>z>0 and then increases with z>0.3. This nonlinear change in Tc is explained as a site preference of Zn ions in the PSZNT system.