Spark plasma sintering of nanocrystalline BaTiO3-powders: Consolidation behavior and dielectric characteristics

BaTiO3 nanopowders prepared by two different wet chemical routes, one based on microemulsion-mediated synthesis (M-BT) and the other one on the alkoxide–hydroxide method (A-BT) were consolidated by spark plasma sintering (SPS). The densification process, the linear shrinkage rates and the relative densities achieved were strongly dependant on the synthetic route. The results show that fully densified BaTiO3 ceramics with a grain size of about 200 nm can be obtained in both cases by controlling the sintering temperature during the SPS process. The study of dielectric properties revealed that M-BT derived ceramics show higher permittivity values compared to those obtained for A-BT. The influence of the barium/titanium ratio on the sintering behavior and the dielectric properties is discussed.