Research of Lead-free Na 0.5 Bi 0.5 TiO 3 -BaTiO 3 System Piezoelectric Ceramics

To reduce the coercive field of Na 0.5 Bi 0.5 TiO 3 , BaTiO 3 were added as dopant materials. Then the (1− x )Na 0.5 Bi 0.5 TiO 3 - x BaTiO 3 ceramic samples were produced in solid synthetic way. The optimum preparation condition and piezoelectric properties of the samples were investigated. The XRD results show that the fabric transites from rhombohedral to tetragonal gradually with the substitution of the Ba 2+ . The morphotropic phase boundaries (MPB) exists in the composition range of 0.06< x <0.10. The scanning electron microscopy (SEM) results show that the growth of the crystalline grain is restrained and the dimension of it turns finer. The study also shows that optimum calcined temperature is 900°C with x <0.06 and 950 °C with x⩾0.06. Suitable sinter temperature is 1 170 °C, and maintained time is 2 hours. Samples in the composition range of MPB exhibit the best piezoelectric performance. The test results show that the remanent polarization and the conceive field of the ceramics decease with the dope of Ba 2+ . In the composition range of MPB, the conceive field exhibits the lowest value.