Effects of MgO coating on the sintering behavior and dielectric properties of BaTiO3

MgO coated BaTiO3 powder prepared by a homogeneous precipitation method revealed an adsorption of fine MgO particles on the BaTiO3 surface. MgO coated BaTiO3 increased the onset temperature of shrinkage, compared with mechanically MgO added BaTiO3. Dielectric constants of MgO mixed BaTiO3 decreased with increasing MgO contents, whereas MgO coated BaTiO3 showed less dependence on MgO contents. The shell phase formation temperature of MgO coated BaTiO3 were higher than the mixed ones. MgO coated BaTiO3 showed smaller lattice parameters compared with mixed samples, where both specimens have the same MgO content. Extra MgO phase was detected on all of the MgO-doped BaTiO3. However, MgO mixed BaTiO3 showed weaker characteristic X-ray diffraction peaks of MgO phase than coated samples.