Solid-State Synthesis and Properties of Relaxor (1 – x)BKT–xBNZ Ceramics

Abstract

Conventional solid-state synthesis was used to synthesize dense and phase pure ceramics in the (1−x) Bi0.5K0.5TiO3–xBi0.5Na0.5ZrO3 (BKT–BNZ) system. Structural characterization was done using X-ray diffraction at both room temperature and elevated temperatures, identifying a transition from tetragonal xBi0.5Na0.5ZrO3 (xBNZ, x = 0–0.10) to pseudo cubic xBNZ for x = 0.15–0.80. Dielectric properties were investigated with respect to both temperature (RT = 600°C) and frequency (1–106 Hz). Relaxor-like behavior was retained for all the materials investigated, evident by the broadening of the relative dielectric permittivity peaks at transition temperatures as well as frequency dispersion at their maximum. The maximum dielectric constant at elevated temperature was found for 0.15 BNZ. Electric field-induced strain and polarization response were also investigated for several compositions at RT and the largest field-induced strain was observed for the 0.10 BNZ ceramics. The composition range with best performance coincides with the transition from tetragonal to cubic crystal structure.