Hydrothermal synthesis, structure and property of nano-BaTiO3-based dielectric materials

A series of Ba_1-xSr_xTi_1-yZr_yO₃ (0≤x≤0.5, 0≤y≤0.4) and BA_1?xZn_xTi_1?ySn_yO₃ (0≤x≤0.3, 0≤y≤0.3) solid solutions were synthesized by low-temperature/low-pressure hydrothermal method below 170°C, 0.8 MPa. XRD pattern and cell parameters-composition figures of these prepared powders demonstrated that they are completely miscible solid solutions based on BaTiO₃. Furthermore, TEM showed that they have a shape of uniform, substantially spherical particles with an average particle size of 70 nm in diameter. The sintered ceramics of those powders doped by Sr²⁺ and Zr⁴⁺ or Zn²⁺ and Sn⁴⁺ have dielectric constant twelve times higher than and dielectric loss 1/6 those of pure BaTiO₃ phase at room temperature.