Effect of MgO addition on the microstructure and dielectric properties of BaTiO3 ceramics

MgO-doped BaTiO3 (BaTiO3/MgO) ceramics were prepared by a solid-state sintering method. The effects of MgO doping on the dielectric properties of BaTiO3/MgO were investigated in terms of its microstructural development. The BaTiO3/MgO was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and x-ray powder diffraction. Results show that grain growth of the BaTiO3/MgO during sintering was inhibited by adding MgO at least 0.5 mol%. It resulted in a high resistance of the BaTiO3/MgO sintered at high temperature. The BaTiO3/MgO possessed a broad temperature stability and met Electronic Industries Association (EIA) x7R specification. The improved dielectric properties of the BaTiO3/MgO are attributed to the decreased tetragonality of BaTiO3 lattice due to Mg2+ substitute for Ti4+.