Effects of Mg-doping on the microstructure and properties of BaTiO3 ceramics prepared by hydrothermal method

Nanosized Mg-doped barium titanate powders were prepared at 240 °C by hydrothermal method using BaCl2·2H2O, TiCl4 and NaOH as the main reactants and MgCl2·6H2O as additive. The effects of Mg-doping on microstructure and properties of BaTiO3 ceramics were investigated by X-ray diffractometer (XRD), atomic emission spectrum (AES) and scanning electron microscopy (SEM) characterizations. As indicated by results, B site (Ti) is substituted by Mg. Mg-doping is helpful to get the microstructure with small grains and high density. Mg has evident function on shifting Curie peak. The value of ΔTc is −40 °C in the doping range of 0 to 0.15 wt%. When Mg/Ti atomic ratio is 0.06 in starting materials, the density reaches the maximum, relative dielectric constant reaches 4,100 and breakdown electric field rises up to 3.0 kV/mm.