Preparation and characterization of Co-doped BaTiO3 nanosized powders and ceramics

The Co-doped BaTiO3 nanosized powders and ceramics were prepared via the sol–gel process. The powders and ceramics were characterized by methods of XRD, SEM and TEM. The dielectric properties of the ceramics were also determined by these methods. The influence of sintering temperature, sintering time and Co concentration on the microstructure and dielectric properties was discussed. The results revealed that the powders were in nanometer scale (30–50 nm) and were mainly composed of cubic BaTiO3 phase and small amount of BaCO3. After sintering, both the cubic BaTiO3 and BaCO3 were transformed into tetrahedron BaTiO3. The sintering temperatures of the Co-doped BaTiO3 ceramics decreased (about 100 °C) and the Curie temperatures of the ceramics were then moved to lower temperature. In addition, the dielectric constant of the ceramics doping with Co was higher than that of the pure BaTiO3 ceramics. The dielectric constant was increased first, and then decreased as the concentration of Co increased.