A study on the synthesis and properties of additives coated BaTiO 3

Abstract

The Powder characteristics and sintering behavior of SiO2 coated BaTiO3 were studied. BaTiO3 powders were synthesized by the liquid mix method developed by Pechini, and silica coating was prepared by alkoxide hydrolysis method with TEOS and ethanol. The particle size of the BaTiO3 powders was 35 nm and the thickness of the SiO2 coating layer was 5 nm. As the SiO2 content increased, the SiO2 layers improved the powder dispersion by increasing electrostatic repulsion between the BaTiO3 particles. Effects of MgO coating on microstructure and dielectric properties of BaTiO3 have been studied compared with mechanically MgO mixed BaTiO3. MgO coated BaTiO 3 particles were prepared by a homogeneous precipitation method using MgCl2-OH2O and urea. MgO coated BaTiO3 exhibited homogeneous microstructure compared with mixed samples. XRD analysis revealed that Mg substitution for the Ti site in the MgO mixed sample was much greater than in the coated one. El ectrical properties of MgO mixed and coated BaTiO3 were affected by the diffusion behavior of Mg in BaTiO3 lattice.