Structural, Optical, Magnetic, Dielectric, and Ferroelectric Properties of BiFe<sub>1−<i>x</i></sub>Co<sub><i>x</i></sub>O<sub>3</sub> Nanoferrites
Kakali Sarkar, Hemant Kumar, Ritu Kumari, Vivek Kumar
Abstract
The present study emphasizes the fabrication of nanostructured BiFe 1− x Co x O 3 ( x = 0.03, 0.05) via a wet chemical route. X‐Ray diffraction confirms the hexagonal crystalline structure of the ferrite and an increase in crystallite size from 33 to 45 nm with a rise in x . The particle size, determined using high‐resolution transmission electron microscopy, increases from 30 to 42 nm with higher cobalt content. The direct band gap is evaluated using diffuse reflectance spectroscopy, showing a decrease from 2.47 to 2.35 eV. The prepared ferrites exhibit broad and strong room‐temperature photoluminescence, with emission wavelengths ranging from 418 to 595 nm, indicating near‐band emissions and oxygen vacancies. Physical property measurement system reveal a decrease in magnetic coercivity from 924 to ≈759 Oe as x increases. Unlike coercivity, an increase in saturation magnetization is found. An increase in the ferroelectric behavior of the prepared ferrites is observed, where both polarization and coercive field increase with cobalt substitution. Moderate magnetic coercivity and a broad P–E loop area suggest the use of these materials in permanent magnets and charge storage. Additionally, these materials may be employed to develop hydroelectric cells due to enhanced defect states, porous structures, and oxygen deficiencies.