Local Structure and Defect Analysis of KVO3 Doped BiFeO3–BaTiO3 Ceramics Facing Conductivity, Permittivity, and Magnetic Properties

This study discovers the effects of KVO3 doping on BiFeO3-BaTiO3 regarding phase transitions, defect formation, and changes in electronic and magnetic behavior. The synthesized material (1-x-y)BiFeO3-xBaTiO3-yKVO3 with (x=0.33, 0.38 and y=0, 0.01) have pseudo-cubic structure, where the FeO6 octahedron was elongated in the z-axis, and Fe has an oxidation state of 3+ and 4+. The electrons in the 3d subshell initially showed a high spin state, transitioning to a low state after KVO3 doping. Further investigation identified phase transition Rhombohedral + Pseudo Cubic to Rhombohedral for FT33 at T∼100oC and Pseudo Cubic phase to Cubic phase for FT38 at T∼200oC. Conductivity at low temperatures ascribed to unbinding electrons, while the presence of defect-creating dipole strengthened the dipole polarization. The magnetization hysteresis of KVO3-doped samples significantly decreased due to the high spin state transformed to the low spin state of the 3d subshell of Fe in the octahedron FeO6.