Dielectric, ferroelectric and ferromagnetic properties of samarium doped multiferroic bismuth ferrite

In this research, un-doped and samarium doped functional bismuth ferrite nanoparticles were synthesized by sol-gel method. The samples were annealed at 600 °C to obtain crystalline phase. The concentration of samarium was varied in bismuth ferrite as Bi1−xSmxFeO3 (where x = 0.05, 0.10 and 0.15). Rietveld refinement was conducted and crystal parameters were extracted. Crystallite size for doped nanoparticles was found to vary from 66 to 44 nm. Doping of 5 and 10% Sm in BFO, the impurity phases were found to suppress totally. The rhombohedral structure of bismuth ferrite with R3c space group has found to transform to orthorhombic structure with Pbam space group in doped samples. The frequency dependence dielectric properties namely dielectric constant, dielectric loss, resistance, reactance, AC resistivity, AC conductivity and modulus of electricity were measured on nanocrystalline solids. The influence in ferroelectric property, P-E hysteresis loop of un-doped and doped samples was also investigated on nanocrystalline solids. The maximum polarization was found to be 0.084 μC cm−2 in Bi0.85Sm0.15FeO3. The coercive field was decreased in doped samples due to suppression of impurity phases and a minimum value was found in Bi0.9Sm0.1FeO3. The M–H hysteresis loop of synthesized nanoparticles has also been determined. The magnetization of doped samples showed an enhanced saturation magnetization and remnant magnetization of 1.87 and 0.57 emu gm−1 respectively in Bi0.85Sm0.15FeO3 nanoparticles.