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.
