Synthesis, Structural, Morphological and Magnetic Properties of La and Mn Codoped Bismuth Ferrite

Abstract

Bismuth Ferrite (BiFeO3) has gained significant importance recently due to its novel multiferroic properties. Owing to its unique physicochemical, optical and magnetic properties, it is extensively used in number of applications such as light-emitting diodes, ferroelectric solar cells, transformers and magnetic shielding. The present research focusses on a simple and easy approach for synthesizing mesoporous gyroidal nanostructures; a template-free technique employing double-solvent sol-gel method for fabrication of La and Mn co-doped BFO nanoparticles. Double solvents including ethylene glycol (EG) and acetic acid were employed in this technique. Bi1-xLaxFe1-yMnyO3 as BFO, Bi0.90La0.10FeO3 (BLFO), Bi0.90La0.10Fe0.95Mn0.05O3 (BLFMO-5), Bi0.90La0.10Fe0.85Mn0.15O3 (BLFMO-15) and Bi0.90La0.10Fe0.80Mn0.20O3 (BLFMO-20) were fabricated by optimizing the conditions in double-solvent sol-gel method. XRD technique was utilized to analyze the phase purity of formation. XRD results revealed that the phase of BFO changed from rhombohedral to orthorhombic by La and Mn co-doping. The structural and morphological analysis of nanoparticles by SEM illustrated the presence of well-ordered mesoporous gyroidal nanostructures in BLFO and BLFMO-5. However, with the increment in Mn concentration (BLFMO-15 and BLFMO-20), the network started degrading with loss of ordered porosity. Further, the presence of mesopores in all nanostructures was confirmed by BET analysis. Magnetic properties of pure BFO and co-doped BLFMO were explored by VSM that reported the increase in ferromagnetism upon La doping. The decrease in magnetization and enhanced coercivity with increased Mn concentration (BLFMO-20) suggests the presence of antiferromagnetic phase in these nanoparticles. The results overall suggest that different codoped BFO mesoporous nanoparticles can be fabricated by employing simple, easy and economical approach for variable magnetic properties.