Ferroelectric phase transition in Bi-doped PLZT ceramics

Polycrystalline samples of [Pb0.92(La1−zBiz)0.08][Zr0.60Ti0.40]0.98O3 (z=0.0, 0.3, 0.6, 0.9, 1) (PLBZT) were synthesized using a high-temperature solid-state reaction technique. The formation of the PLBZT compounds in a particular crystallographic phase as a function of Bi concentration was checked through X-ray diffraction (XRD). S.E.M. study of PLBZT with higher magnification and resolution shows the uniform distribution of particles/grains on the surface of the samples. Dielectric constant and tangent loss of the samples in wide temperature and frequency range provided the nature of phase transition. The diffuse phase transition was observed for higher z. An increase in permittivity maxima temperature (i.e. the transition temperature) was also observed with increasing Bi concentration. The values of resistivity of all the samples are very high (109 Ω-cm).