Structural, magnetic, and electrical properties driven by monovalent Li substitution on Bi1-xLixFeO3 (0 ≤ x ≤ 0.1) ferrites

A series of Bi1-xLixFeO3 (0.0 <= x <= 0.1) compounds with monovalent substitution have been synthesized via sol-gel techniques to examine how Li substitution affects their structural, microstructural, magnetic, ferroelectric, and dielectric properties. The Rietveld-fitted X-ray diffraction analysis shows that all samples crystallize in a rhombohedral structure with R-3c crystal symmetry, and the lattice parameters vary due to the ionic size mismatch between Bi and Li cations. Additionally, the particle size, determined by the Scherrer equation, and the grain size, measured by scanning electron microscopy, decrease by substituting monovalent Li cations. The room temperature Raman spectroscopy shows the reduction of Raman shift as doping concentration increases. Notably, doped compounds' saturation magnetization (Ms) significantly increases with higher Li-doping. This observation suggests that the exchange interactions between Fe-O-Fe have been enhanced, resulting in spatial modulation for the destruction of the helical structure. Furthermore, increased polarization and leaky behavior are observed with increasing Li content. These findings provide valuable insights for tailoring the properties of BiFeO3-based compounds for potential applications in various fields such as spintronics, multiferroics, and sensors.