Doping Effects on the Piezoelectric Properties of Low-Temperature Sintered PbTiO 3 -Based Ceramics for SAW Applications

The Sm-modified lead titanate ceramics with a composition of (Pb0.85Sm0.1) (Ti0.98Mn0.02)O3 piezoceramics, doped and undoped with BiFeO3 (BF) and Ba(Cu0.5W0.5)O3 (BCW) oxides, were prepared by conventional mixed-oxide method, using sintering temperature at 1075°C and 1100°C. Microstructural and compositional analyses of the PbTiO3-based ceramics have been carried out using XRD and SEM. The effects of dopants on the sintering temperature and piezoelectric properties of the ceramics have been investigated. We successfully showed that these additives were helpful in lowering of the sintering temperature and still keep high thickness electromechanical coupling coefficient, kt, and small planar electromechanical coupling coefficient, kp. Surface acoustic wave (SAW) filters were fabricated and the phase velocities were measured.