Dy doped BiFeO3: A multiferroic with bulk structural and ferroelectric properties comparable with nano counterparts

Abstract

The structural and ferroelectric properties of Dy doped BiFeO3 multiferroic materials are reported. The bulk polycrystalline Bi0.9Dy0.1FeO3 samples were synthesized using solid state reaction technique and their nano counterparts were prepared using ultrasonic probe sonication. XRD patterns demonstrated significant improvement of phase purity due to Dy substitution both in bulk sample and corresponding nanoparticles. Again, FESEM imaging was carried out to analyze the surface morphology of bulk sample as well as to determine the size and distribution of the synthesized nanoparticles. Furthermore, leakage current density measurements were performed where, interestingly, we found comparable performance for Bi0.9Dy0.1FeO3 bulk and its corresponding nanoparticles. Moreover, the polarization versus electric field measurements showed higher remanent polarization and coercive field for nanoparticles compared to their bulk samples which might be associated with leaky behavior generated from oxygen related defects of the nanoparticles. However, saturation polarization within the applied field range was observed for Bi0.9Dy0.1FeO3 bulk only indicating inherent ferroelectric behavior. Overall, this investigation provides evidence of Bi0.9Dy0.1FeO3 multiferroic having enhanced structural purity and ferroelectric properties over undoped BiFeO3. In particular, it opens up the pathway of a material with equivalent bulk and nano leakage current performance which may be useful in many applications.