MgO Effect on The Dielectric Properties of BaTiO3

The dielectric properties of barium titanate as functions of the MgO addition in various rates are investigated in this paper. The ceramics were prepared by conventional methods. X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry, were applied to determine the structure and microstructure of the studied material. Phases MgO, TiO and TiO₂, have been detected. Decrease of the grain size with increasing MgO content was observed. Measurements of εr, tgδ and resistance have been performed at temperatures ranging from 30⁰C to 400⁰C. The electric permittivity (εr) showed a considerable decrease with increasing MgO concentration. Additionally, for low MgO concentration (≤mol.% MgO) a shift of the dielectric loss peak (tgδ_m) towards low temperatures was observed. When the MgO content was ≥15mol.% MgO the tgδ_m moved into higher temperatures. The obtained results indicate that the substitution of Mg²⁺ ions in B-site ions (Ti⁴⁺) had a significant influence on the values of εr, tgδ and the resistance increase of the ceramics.