Influence of Rare-Earth and transition metal substitution on structural and dielectric properties of BiFeO3

We hereby report synthesis and characterizations of BiFeO3 (BFO), Bi0.9La0.1FeO3 (BLFO), Bi0.9La0.1Fe0.9Zn0.1O3 (BLFZO) perovskites. The influence of doping La3+ at Bi-site and Zn2+ at Fe-site are investigated in addition to the impurity phases appearing in the synthesized samples. We characterized these samples with X–ray diffraction (XRD) technique to disclose crystal structure acquired. The calculated lattice parameters for BFO, BLFO and BLFZO phases witness the presence of trigonal structure with little variations attributed to varied ionic size of host and guest site ions. The average crystallite size calculated from characteristic peak for BFO, BLFO and BLFZO ceramics were 59.33nm, 81nm and 67.20 nm respectively. From the study of the dielectric nature of these ceramics, it was found that that BLFO exhibits high dielectric constant compared to BFO and BLFZO samples. The loss values of all the samples reported was found relatively very low. The low dielectric constant of BFO and BLFZO in comparison to BLFO can be attributed to the presence of impurity phase with larger fractional percentage. The ac Conductivity study reveals the dc current contribution up to certain field value but in the higher region of applied field, the ac contribution overshadows dc current.