Implications of La and Y Codoping on Structural, Multiferroic, Magnetoelectric and Optical Properties of BiFeO3

Polycrystalline phase pure BiFeO3 (BFO) and codoped Bi0.95La0.05Fe1-xYxO3 (with x = 0.05, 0.10, 0.15 and 0.20) ceramics have been prepared via sal gel process. Subsequently, the effects of Y codoping on structural, dielectric, magnetic, magnetoelectric and optical properties have been investigated for various Y concentrations, and compared with those of undoped BiFeO3. The Rietveld refinement analysis of X-ray diffraction patterns of La and Y codoped ceramics shows the structural transition from rhombohedral to orthorhombic phase for x >= 0.10 doping concentration of Yttrium. Field emission scanning electron micrographs reveal the presence of interconnected spherical grains. It is observed that an increase in the codoped Y content in BiFeO3 significantly enhances the dielectric constant, magnetization and magnetocapacitance while there is decrement in the average grain size of particles and the band gap. These positive implications of codoping of La and Y in BiFeO3 make such a class of materials to be more promising from the device application point of view.