Raman scattering spectra and ferroelectric properties of $Bi1−xNdxFeO3$ $(x=–0.2)$ multiferroic ceramics Available to Purchase

Single-phase $Bi1−xNdxFeO3$ $(BNFOx)$ $(x=0–0.2)$ multiferroic ceramics were prepared to study the effects of Nd substitution on their crystal structures, Raman scattering spectra, and ferroelectric properties. Rietveld refinement of x-ray diffraction data showed a gradual change in crystal structure from rhombohedral to pseudotetragonal via triclinic with increasing $x$⁠. The evolvement of Raman normal modes with increasing $x$ suggested that such structural change is accompanied by the weakening of long-range ferroelectric order. The simultaneous occurrence of abrupt mode evolvement and ferroelectric-paraelectric transition in $BNFOx=0.175$ and $BNFOx=0.2$ was explained according to the change of Bi–O covalent bonds as a result of the decline in the stereochemical activity of the Bi lone electron pair at $0.175⩽x⩽0.2$⁠.