Structural, Ferroelectric and Magnetic Properties of NiTiO₃–CoTiO₃ Solid Solutions Synthesized by Sol–Gel Method.

The Ni 1 − x CoxTiO3 (0 ≤ x ≤ 1) solid solution powders were prepared by an aqueous sol–gel method. The structural, optical, magnetic and ferroelectric properties of NiTiO3 were investigated by X-ray diffraction, scanning electron microscope, UV–Vis absorption, vibration samples magnetometer and ferroelectric test system. The X-ray diffraction analysis revealed that prepared materials were in a single phase with rhombohedral structure with x up to 1. The increasing Co content resulted in decreasing of tolerance factor and increasing of the lattice constant. The crystalline size increased with an increase of Co content. The optical bandgap value of solid solution increased from 2.23 eV for NiTiO3 to 2.36 eV for CoTiO3. The magnetic hysteresis loop results indicate that all samples showed paramagnetic state at room temperature. A correlation between magnetization values and composition of the materials was observed with magnetization values which increased with increasing of CoTiO3 content in solid solution. Ferroelectric polarization analysis showed that the polarization of the Ni 1 − x CoxTiO3 solid solution depended on x value and reached the maximum with x = 0. 4. [ABSTRACT FROM AUTHOR]