Research of Lead-free Na0.5Bi0.5TiO3-BaTiO3 System Piezoelectric Ceramics

To reduce the coercive field of Na0.5Bi0.5TiO3, BaTiO3 were added as dopant materials. Then the (1-x)Na0.5Bi0.5TiO3-xBaTiO(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 Ba2+. 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 degrees C with x<0.06 and 950 degrees C with x > 0.06. Suitable sinter temperature is 1 170 degrees 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 Ba2+. In the composition range of MPB, the conceive field exhibits the lowest value.