Enhancing dielectric properties of CuFe₂O₄ spinel ferrites through Mg, Co, and Cr doping: a sol-gel synthesis approach

The exploration of spinel ferrites, particularly those with the formula AFe₂O₄, has gained considerable interest owing to their structural, electrical, and optical features. This study focuses on enhancing the dielectric properties of CuFe₂O₄ ferrite through doping with Mg, Co, and Cr. Using the sol-gel technique, we synthesized Cu_0.5Mg_0.3Co_0.2FeCrO₄ (CMCFCO) sintered at 950 °C. The CMCFCO material was characterized by X-ray diffraction, scanning electron microscopy, and impedance spectroscopy to understand its crystallographic structure, morphology, and dielectric properties. Microstructural analysis confirms a cubic phase with an average grain size of 1.70 µm. Impedance spectroscopy reveals a transition from insulating to semiconductor state at 360 K, indicating temperature-dependent non-Debye relaxation processes. The material exhibits a high dielectric constant, making it suitable for high-frequency applications. Our findings suggest that Mg, Co, and Cr doping influences the electrical conductivity and the dielectric constant, making CMCFCO a candidate for further exploration in high-frequency devices. This research contributes to the development of advanced spinel ferrites with tailored properties for specific technological applications.