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The bismuth layer structured ferroelectric (BLSF) ceramics consisting of four-layers (BaLa0.75Bi3.25Ti4O15) and five-layers (Ba2La0.75Bi3.25Ti5O18) were prepared by the conventional solid-state reaction method. Summerfield ac-conductivity scaling analysis was used to evaluate the electrical behavior and the ac-conductivity isotherm curves. The relaxation results were corroborated with the Raman Peak positions and full width at half maximum was obtained by using Lorentzian peak fit method. Finally, the results were compared with the two-layered relaxor-compound (Bi2.45La0.55TiNbO9) and technologically standard three-layered compounds (La0.75Bi3.25Ti3O12; BLT). The dielectric relaxation of Bi2.45La0.55TiNbO9was verified using modified Curie-Weiss law and Vögel-Fulcher relationship. An attempt is made to realize the typical collective nature of the ionic conductivity of the samples. [ABSTRACT FROM AUTHOR]

Tri (Dy3 +) and pentavalent (Nb+5) modified new polycrystalline material of Aurivillius family (Dy0.75Bi3.25Ti2.9625Nb0.03O12) was prepared by solid-state reaction method and the lattice parameters were calculated by using X-ray diffractogram. Impedance measurements were carried out from room temperature to 500°C in the frequency range of 100 Hz to 1 M Hz. Impedance spectroscopic plots show non-Debye type and detailed ac-conductivity analysis was also employed to understand the heterogeneity of the present electro-ceramics. The results were corroborated with the proposed defect formula and in addition, thermal stimulated current measurements show that the present sample has an excellent pyroelectric response. [ABSTRACT FROM AUTHOR]

A and B site modified new bismuth layered structure ferroelectric ceramics of the Aurivillius family were prepared by the solid-state route. Impedance measurements were performed on these samples to understand the relaxation effects in the frequency range of 100 Hz to 1 MHz. From the detailed impedance and modulus spectroscopic analysis, it is found that the aliovalent modified B-site enhances the relaxor-like nature, compared to A-site substitution. These results were corroborated with ac-conductivity transport analysis. In this connection, a defect formula is also proposed. The results are discussed. [ABSTRACT FROM AUTHOR]