Optical, Ferroelectric, and Magnetic Properties of NiTiO3–CoFe2O4 Composites Prepared by One-Step Sol–gel Method

The mixed spinel—ilmenite nanocomposites of (1 − x)NiTiO3–xCoFe2O4 (x = 0, 0.05, and 0.10) have been synthesized by sol–gel method. In a one-pot synthesis method, both the constituent phases of composites are formed during the same time of the synthesis process. X-ray powder diffraction gave evidence of the phase purity of the systems. CoFe2O4 phase modified the optical band gap of NiTiO3 materials, shifted the optical band-gap value NiTiO3 toward lower energy. Optical band-gap values decreased from 2.23 to 1.51 eV for pure NiTiO3 and 10 mol% CoFe2O4-modified NiTiO3 samples, respectively. NiTiO3–CoFe2O4 composites with 5 and 10 mol% CoFe2O4 fractions were found to enhance the ferroelectric and magnetic properties of NiTiO3 at room temperature. The remanent polarization (Pr) increased from 0.017 to 0.182 µC/cm2 and saturation polarization (Ps) increased from 0.056 to 0.219 µC/cm2 for NiTiO3 and 10 mol% CoFe2O4-modified NiTiO3 sample, respectively. The saturation magnetization (Ms) and remanent magnetization (Mr) of the samples increased with increasing of CoFe2O4 fraction. The increasing of Ms and Mr of composites indicated the strong dependence of magnetic properties on CoFe2O4 addition.