DIELECTRIC AND FERROELECTRIC PROPERTIES OF (Li, Ce)-DOPED Sr2Bi4Ti5O18 LEAD-FREE CERAMICS

The influence of (Li, Ce) doping on the electrical properties of bismuth layer Sr2-x(Li, Ce)x/2Bi4Ti5O18 [abbreviated to SBTi-(Li, Ce)X/2] ceramics was investigated. X-ray diffraction analysis showed that all the ceramic samples were single-phase compounds. The (Li, Ce) modification significantly decreased the dielectric loss of Sr2Bi4Ti5O18 ceramics and greatly improved the piezoelectric activity. At x/2 = 0.0125, the SBTi-(Li, Ce)x/2 ceramics exhibited the excellent properties with high remnant polarization (Pr = 9.3 μC/cm2) and high Curie temperature (Tc = 299°C). Meanwhile, the SBTi-(Li, Ce)0.0125 ceramics had the largest piezoelectric constant (d33 = 26 pC/N). The results showed that the SBTi-(Li, Ce)x/2 ceramic was a promising lead-free piezoelectric material.