Study on the microstructure and dielectric properties of X9R ceramics based on BaTiO3

This paper investigated the microstructure and dielectric properties of BaTiO3-Pb(Sn, Ti)O3 system ceramics. The Curie point of BaTiO3 is 130 °C. When the temperature is higher than 130 °C, the dielectric constant of BaTiO3 drops severely according to Curie–Weiss law. Pb(Ti, Sn)O3(PTS) was selected to compensate the dielectric constant doping of BaTiO3 since it has high Curie temperature (Tc) point that is about 296 °C. The Curie temperature (Tc) point of BaTiO3 was broadened and shifted to higher temperature because of the doping of PTS, so the temperature coefficient of capacitance (TCC) curves of the ceramics based on BaTiO3 was flattened. When 2 wt% Pb(Ti0.55Sn0.45)O3 was added, the sample showed super dielectric properties that the dielectric constant was >1750 at 25 °C, dielectric loss was lower than 2.0% and TCC was <±10% from −55 °C to 200 °C. Therefore the materials satisfied EIA X9R specifications.