Electrical properties of donor- and acceptor-doped BaBi4Ti4O15

The electrical properties of the BaBi4Ti4O15 compound, a member of the family of Aurivillius bismuth-based layer-structure perovskites, have been studied as a function of aliovalent doping and processing conditions. The samples were prepared by reaction sintering or hot forging of a mixture of BaTiO3 and Bi4Ti3O12 with Nb substituted for Ti, as a donor dopant, and Fe as an acceptor. The dielectric constant of BaBi4Ti4O15 is increased by both dopants. Nb doping decreases the Curie temperature, while Fe doping increases it. The conductivity of BaBi4Ti4O15 is p-type and it is decreased by Nb doping and increased by Fe doping. The incorporation of aliovalent dopants into the BaBi4Ti4O15 structure, is however, preferentially compensated by the change in the composition of the compound.