Experimental visualization of the Bi–O covalency in ferroelectric bismuth ferrite (BiFeO3) by synchrotron X-ray powder diffraction analysis†
Abstract
The experimental electron-density distribution of ferroelectric bismuth ferrite (BiFeO3) has been visualized using the synchrotron X-ray powder diffraction data and the maximum-entropy method. The present work has clearly revealed the partial covalency of the Bi–O bond, which is a key to understand the spontaneous polarization. Density functional theory (DFT) calculation has supported the validity of the experimental results.