Dielectric, ferroelectric properties, and grain growth of CaxBa1-xNb2O6 ceramics with tungsten-bronzes structure.

Dielectric properties, microstructures, and phase transition behaviors of α and β phases of CaxBa1-xNb2O6 (x=0.22, 0.30, and 0.38) ceramics were investigated. All the three compositions had partially filled tungsten-bronze structure (TTB) and relatively high Curie temperatures (up to 345 °C) compared with Sr1-xBaxNb2O6. The α phase exhibits unambiguously a diffused phase transition, while the β phase is associated with an incommensurate phase and needs to be further studied. The dielectric and ferroelectric properties of CaxBa1-xNb2O6 ceramics were strongly processing-dependent. A mechanism was proposed to explain the grain growth behavior of TTB ceramic niobates. [ABSTRACT FROM AUTHOR]