Impedance and Raman Spectroscopic Studies on La-modified BLSF Ceramics

Abstract

The bismuth layer structured ferroelectric (BLSF) ceramics consisting of four-layers (BaLa_0.75Bi_3.25Ti₄O₁₅) and five-layers (Ba₂La₀.₇₅Bi_3.25Ti₅O₁₈) 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 (Bi_2.45 La_0.55TiNbO₉) and technologically standard three-layered compounds (La_0.75Bi_3.25Ti₃O₁₂; BLT). The dielectric relaxation of Bi_2.45La_0.55TiNbO₉ was 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.

Keywords:

• BLSF
• impedance
• Raman studies
• ac-conductivity
• scaling law