Ferroelectric relaxor properties of (1 − x)K0.5Na0.5NbO3–xBa0.5Ca0.5TiO3 ceramics

The Ba0.5Ca0.5TiO3 (BCT) composition dependent dielectric and structural properties of (1−x)K0.5Na0.5NbO3–xBa0.5Ca0.5TiO3 powders were investigated. Room temperature x-ray diffraction revealed the powder structure to transform from orthorhombic to cubic with increasing BCT composition. The frequency dependent dielectric constant measurements revealed a shift in the temperature of the maximum dielectric constant for at frequencies, suggesting that the system exhibits ferroelectric relaxor behavior. The system containing 15% BCT showed the closest calculated Curie–Weiss exponent to 2, which the exponent for a relaxor ferroelectric.

► The physical properties of Pb-free relaxor ferroelectric ceramics are studied.
► Room temperature XRD revealed the structure to transform with BCT concentration.
► 15% of BCT sample showed the closest calculated Curie–Weiss exponent to 2.