The structural and electrical properties of pure and manganese doped barium titanate (BaTiO3) with a general formula BaMnxTi1-xO3 (where x=0.00, 0.01, 0.02, 0.03, and 0.04) were investigated. For the observation of the surface morphology and estimation of grain sizes scanning electron microscopy (SEM) was employed. The grain size of BaTiO3 increased with an increase of the Mn doping. The Curie temperature (Tc) which indicates the tetragonal-to-cubic transition, of each sample was found from the resistivity versus temperature curve, and Tc of BaTiO3 increased linearly with an increase of the Mn doping. The Tc of un-doped BaTiO3 was lower than that of the doped samples. The Tc value of pure BaTiO3 was found to be 120 oC. It was found that the dielectric constant versus temperature curve also shows a similar type of Tc. The dielectric constant of BaMnxTi1-xO3 was found to decrease with an increase of Mn doping and the Tc of BaTiO3 increases with the addition of Mn.

Keywords: Surface morphology, Grain size, Transition temperature, DC resistivity, Dielectric constant.