Structural, electrical and magnetic properties of rare-earth and transition element co-doped bismuth ferrites

Pure and doped multiferroic samples of bismuth ferrites (BFO) were successfully synthesized by the sol-gel technique. Detailed investigations were made on the influence of (Sm and Mn, Co, Cr) co-doping on structural, electrical, ferroelectric and magnetic properties of the BFO. A structural phase transformation from rhombohedral to orthorhombic with co-doping is confirmed through XRD. It is also observed that Sm-doping increases the symmetry and decreases the second phases noticeably. Microstructure investigation using the scanning electron microscope showed a reduction of grain size with doping in BFO. Magnetic hysteresis loops showed that retentivity (Mr), coercivity (Hc) and saturation magnetization (Ms) of the doped samples were improved. Furthermore, the co-doping enhances the dielectric properties as a result of the reduction in the Fe2+ ions and oxygen vacancies. The room temperature P-E loop study shows that ferroelectric properties are strongly depend on doping.