Abstract
The structure and electrical properties of bismuth‐doped (Ba~1–x~ Ca~x /2~Sr~x /2~)TiO~3~(BCST) (x ≤ 0.40) ceramics prepared using the solid‐state reaction were investigated. X‐ray diffraction (XRD) analysis shows that 5 at% of Bi doping can be fully incorporated into the perovskite lattice of BCST ceramics. BCST ceramic samples for x < 0.40 have almost the same T~m~ (T~m~ is designated as the temperature of the peak dielectric constant, at T~m~ where the dielectric peak occurs) for different frequencies, while an obvious dielectric relaxation behavior (DRB) is observed in Bi‐doped BCST. Bi doping causes T~m~ to shift to a lower temperature and results in an increase in the degree of diffusion and relaxation of the BCST ceramics. A random electric field is suggested to be responsible for the relaxor behavior observations. Double‐hysteresis loops are observed at lower temperatures in Bi‐doped BCST ceramics. The P–E relationship of Bi‐doped BCST ceramics shows the dielectric quasilinearity, which indicates that the random local field acts to strongly inhibit the nanodomains. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)