Studies on electrical properties of SrBi4Ti4-3xFe4xO15

The system SrBi4Ti4-3xFe4xO15 belonging to bismuth layer structured ferroel ectric (BLSF) materials with x = 0, 0.1 and 0.2 has been prepared through s olid-slate double sintering method. Increase of iron content in SrBi4Ti4O15 resulted in densification of the samples. The normal puckering observed in the sample has been found to decrease and the lattice distortion increased , Dielectric measurements indicate the ferroelectric transition temperature of the samples to be 530 degrees C, 560 degrees C and 606 degrees C. The i ncrease of transition temperature with increasing iron content is correlate d with lattice distortion, Conductivity measurements show two slopes and th e activation energies have been found to increase with the iron content. Im pedance spectroscopy measurements confirm insulating behaviour at lower tem peratures. With increase in temperature the samples become conducting and s how relaxational effects. The Cole-Cole plots at higher temperatures are fo und to be semicircles. The relaxation times decrease with the increase of i ron content.