Multiferroicity in sol–gel synthesized Sr/Mn co-doped BiFeO₃ nanoparticles

A simple and cost effective sol–gel auto-combustion technique was used to synthesize Bi_0.9Sr_0.1Fe_1−xMn_xO₃ (x = 0, 0.05, 0.10, 0.15 and 0.20) multiferroics. Rietveld’s refined X-ray diffraction patterns validated the synthesis of pure phase bismuth ferrite nanoparticles adopting a rhombohedrally distorted ABO₃ type perovskite structure with space group R3c. Morphology of the prepared samples manifested the improved crystallinity with increasing Mn contents in BiFeO₃. Uniformly distributed multi-shaped grains having varying sizes were formed after combustion which would affect the microstructural related properties of the parent compound. Energy dispersive X-ray spectroscopy confirmed the presence of the relevant elements in the prepared compositions according to their stoichiometric ratio. Enhanced saturation magnetization was observed with increasing doping concentration in the parent compound. Improved polarization versus electric field loops were observed in Mn and Sr co-doped BiFeO₃ nanoparticles. All the properties in the present research work have been explained on the basis of dopants and their concentrations, phase purity, microstructure and grain sizes.