Thermally-induced local structural transformations in Na0.5Bi0.5TiO3-KNbO3 ceramics

The local symmetry of (1-x)Na0.5Bi0.5TiO3-xKNbO3 (NBT-xKN, x = 0.01−0.07) ceramics was thoroughly examined using high-energy synchrotron x-ray scattering and analysed using the pair distribution function (PDF) method. At room temperature, the structure of NBT-xKN (x = 0.01−0.07) ceramics was best refined using monoclinic C1c1 structures within the local-range (r<22 Å) and rhombohedral R3c within medium-range (22 Å 420 °C (above the temperature of the maximum dielectric peak, Tm), as confirmed by in-situ temperature-dependent PDF analysis.