Effects of Ba0.7Sr0.3TiO3-based buffer layers and La/Mn doping on the crystallization behavior and multiferroic properties of BiFeO3 thin films

Abstract

A detailed study of the BiFeO₃ (BFO)-based bilayer films with improved multiferroic properties is reported. The BFO film without any impurity phase was obtained using Ba_0.7Sr_0.3TiO₃ (BSTO) as a buffer layer. And the leakage currents of the bilayer film were found to reduce effectively through La and Mn co-doping of the BFO Layer. Moreover, magnetodielectric response and ferroelectric domains were observed in the Bi_0.9La_0.1Fe_0.95Mn_0.05O₃ (BLFMO)/BSTO film. We additionally investigated the effects of the BSTO–Ni_0.8Zn_0.2Fe₂O₄ (NZFO) buffer layer on the multiferroic performances and surface morphology of the BLFMO film. It was found that the BSTO–NZFO composite film could significantly enhance the magnetic and magnetodielectric properties of the BLFMO film. In particular, the BLFMO/BSTO–NZFO film possessed a higher coercivity value as compared to the BLFMO/BSTO film.