Electron density distribution influencing the electrical and magnetic properties of polycrystalline Bi${}_{0.9}$Sm${}_{0.1}$FeO${}_3$ ceramics

This article reports the structural properties that influence the electrical and magnetic behaviours of polycrystalline Bi${}_{1-x}$Sm${}_x$FeO${}_3$ (x = 0, 0.1) ceramics. The samples are synthesized by a two-step solid state reaction. X-ray diffraction patterns expose two characteristic peaks corresponding to (104) and (110) planes around 31°. Bi${}_{1-x}$Sm${}_x$FeO${}_3$ (x = 0, 0.1) samples crystalize primarily in the R3c phase along with the traces of secondary phases. The Rietveld refinement analysis reveals that the tilt angle of Bi${}_{0.9}$Sm${}_{0.1}$FeO${}_3$ reduces due to the twisting of FeO${}_6$ octahedra compared to pristine BiFeO${}_3$. The electron density distribution and type of bonding are analyzed using the maximum entropy method. The microstructural analysis reveals that the Bi${}_{0.9}$Sm${}_{0.1}$FeO${}_3$ sample has a reduced average particle size compared to pristine BiFeO${}_3$. The influence of samarium ions in the bismuth site deviates the canting angle of the modulated spiral spin arrangement and the charge density distribution of the Bi${}_{0.9}$Sm${}_{0.1}$FeO${}_3$ sample as a result, the electrical and magnetic behaviours are improved compared with bare BiFeO${}_3$.