Effect of Pb(Ti,Sn)O_3 doping and sintering temperature on dielectric properties of novel temperature-stable BaTiO_3-based X8R ceramics

摘要

The novel temperature-stable X8R dielectric materials could be sintered at 1180°C by doping Pb(Ti,Sn)O_3 additives into the BaTiO_3 ceramics, with a dielectric constant greater than 1550 at 25°C, dielectric loss lower than 2.0% and temperature coefficient of capacitance less than +15% from -55 to 180°C. The effects of Pb(Ti,Sn)O_3 additives and sintered temperature were discussed. Pb(Ti,Sn)O_3 can not only enhance the dielectric constant , but also improve the temperature stability of the BaTiO_3 ceramics effectively. The enhancement of Ti~(4+')s polarisation and the smaller thickness of average grain shell resulted in increase in the dielectric constant. Sintered at a higher temperature, the temperature-capacitance curve was flattened. The decrease in the volume ratio of grain core to grain shell was helpful to improve the temperature stability.