Effect of sintering atmosphere on densification and dielectric characteristics in Sr0.5Ba0.5Nb2O6 ceramics

Ferroelectric Sr0.5Ba0.5Nb2O6 ceramics with a tetragonal tungsten bronze structure were sintered in an atmosphere with a different oxygen partial pressure (Po2). The densification and diffuse phase transition (DPT) behaviors of the ceramics were examined. The density of the sintered body increased as the Po2 of the sintering atmosphere increased, and the optical transmittance and the dielectric constant increased accordingly. However, the Curie temperature decreased. It is explained from a viewpoint of the internal stress on the sample, which is dependent on the porosity.