Electrical transport properties of La doped BiFeO3-NaNbO3 composite

ABSTRACT The composites, (1−x)(BiFe1-yLayO3)– xNaNbO3 with x = 0.25, 0.45 and y = 0.10, 0.20, are prepared by mixed oxide method. XRD analysis shows rhombohedral (hexagonal) structure at room temperature. The properties such as dielectric loss (tanδ) and dielectric constant (ϵr ) of all the samples are studied. A significant improvement in dielectric constants has been observed with the rise of Lanthanum (La) content. A dielectric anomaly above 350°C is observed for all the studied materials. Further, it is observed that ac conductivity (σ ac) spectrum obeys universal Jonscher’s power law. The variation of σ ac with inverse of temperature for all the samples is found to obey the Arrhenius equation. The formation of loop in polarisation verses electric field curve establishes the ferroelectric (FE) nature of all the studied samples. Current (I)-Electric Field (E) loops is studied to show the behaviour of domain switching.