Dielectric properties and phase transitions of BiNbO4 ceramic

In the present work, HP-BiNbO4 was found, by in situ X-ray diffraction, thermal expansion and differential thermal analysis, to transform to orthorhombic BiNbO4 at around 680 °C along with an abrupt increase of volume, and to then transform to the triclinic BiNbO4 at around 1000 °C with an endothermic phenomenon. The results indicate that the dielectric permittivity of HP-BiNbO4 ceramic prepared via the high-temperature/high-pressure method was increased remarkably and this might work in other dielectric systems.