The influence of Cd doping on the surface acoustic wave properties of Sm-modified PbTiO3 ceramics

The Sm-modified lead titanate ceramics with a composition of (Pb0.85−xCdxSm0.1)(Ti0.98Mn0.02)O3; x=0.01–0.08 were prepared by conventional mixed-oxide method. Dielectric and piezoelectric properties of these doped ceramics were measured at room temperature. Microstructural and phase content analyses have been carried out using SEM and XRD. The Curie point versus the amount of Cd composition was also investigated. Surface acoustic wave (SAW) properties, including phase velocity, electromechanical coupling coefficient and temperature coefficient of frequency, were measured. The experiments successfully showed that Cd additive is helpful to obtain higher phase velocity and high electromechanical coupling coefficient, and improve the temperature coefficient of frequency (TCF). In addition, it also reduces the sintering temperature of processing. The SAW properties of our samples (Vp, IL, k2, and TCF) compare well to the commercially-made PZT and PT samples.