Dielectric and ferroelectric responses of Ba0.99 − xBi2x/3Ca0.01Zr0.02Ti0.98O3 ceramics

Structure, dielectric and ferroelectric properties of Ba0.99 − xBi2x/3Ca0.01Zr0.02Ti0.98O3 (x = 0.00, 0.03, 0.06 and 0.12) ceramics have been investigated. X-ray diffraction and Raman results show that Bi3+ ions enter the crystal lattice, maintaining the perovskite structure. Dielectric spectroscopy shows that all compositions sintered at 1350 °C show a normal ferroelectric characteristics. Interestingly, the sample with x = 0.12 sintered at 1150 °C exhibits a relaxor behavior with the frequency dependence of permittivity peak obeying the Vogel–Fulcher formula, which may be ascribed to the defect pair [BiBa⋅−VBa′′]. As the Bi3+ substitution level is increased, the spontaneous polarization is decreased, whereas the coercive field is increased.

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