NiTiO₃/MnFe₂O₄ ferrite composites: synthesis, optical, ferroelectric and magnetic properties

This work reported the successful synthesis of ilmenite-spinel (1 − x)NiTiO₃-xMnFe₂O₄ (x = 0, 0.05 and 0.10) composites by a simple sol-gel method. Phase formation of composites was analyzed by the X-ray diffraction method. All the synthesized samples formed diphasic ilmenite-ferrite composites without any trace of impurity or intermediate phase. The optical properties of synthesized composites were characterized by diffuse reflectance UV–visible spectroscopy. MnFe₂O₄ phase modified the optical band gap of NiTiO₃ material and shifted its optical bandgap value toward lower energy. Ferroelectric and magnetic hysteresis loops were investigated at room temperature. The hysteresis loops indicated the typical ferromagnetic and ferroelectric nature of all composites at room temperature. In P-E loops, the remanent polarization (P_r) and saturation polarization (P_s) showed a slight increase in the sample with 5% MnFe₂O₄ phase addition. However, the lossy P-E loop was observed in the sample with the addition of 10% MnFe₂O₄. The presence of ferrite MnFe₂O₄ phase in NiTiO₃ material enhanced the magnetic properties of NiTiO₃ at room temperature. The M-H loops of NiTiO₃-MnFe₂O₄ composites presented a ferromagnetic behavior with a dramatic increase in saturation magnetization with an increase of ferrite phase addition.