Effect of the Inclusion of Lead on the Dielectric Response of Doped Titanates

Titanate oxides with composition Ba(1-y)PbyTiO3 have been prepared by solid method. The presence of a single phase was confirmed by XRD. The average values of grain sizes are between 0.24 and 1.08 μm. The characterization by dielectric spectroscopy between 20 Hz to 1 GHz, reveals that ɛŕ presents dispersion at lower frequencies and remains constant from approximately 1 MHz. The inclusion of low content of lead (y<0.4) in the perovskite networkof BaTiO3 increases the real dielectric permittivity in a wide range of frequencies(from 120 Hz to 1 GHz). The greatest dielectric losses are observed for BaTiO3 and PbTiO3, so that the partial replacement of barium by lead improves the dielectric properties of the material. The imaginary versus real permittivity diagramssuggest that the electrical resistance corresponding to grain boundaries could be higher than that for grains.