Ferroelectric and piezoelectric properties of tungsten doped CaBi4Ti4O15 ceramics

Tungsten doped CaBi4Ti4O15 (CBT) ceramics was prepared by solid-state reaction method. A pure single phase of layer-structured ferroelectric with m=4 was formed when x <= 0.025. The effect of W doping on dielectric, ferroelectric and piezoelectric properties was investigated. W6+ doping increased the temperature stability of dielectric constant and decreased dielectric loss. W6+ doping decreased the remanent polarization, while the coercive field decreased as well, as a result, the piezoelectric constant was increased. AC conductivity measurement showed that W6+ doping increased the conductivity of CBT ceramics and showed n-type conducting mechanism. W6+ doped ceramics has smaller activation energy due to many defects introduced in the crystal lattice.