Investigation of Magnetic and Dielectric Properties of Nanofibric Spinel Oxides ACo2O4 (A = Co, Ni, and Fe) Under Low Magnetic Field

In this study, nanofibric cobaltites were synthesized using the electrospinning technique. The research focuses on how Ni and Fe cation substitutions affect the magnetic and dielectric properties of ACo₂O₄. X-ray diffraction analysis confirmed that all synthesized samples possess a cubic spinel structure. FESEM revealed that the cobaltite samples have a nanofibric morphology composed of interconnected nanoparticles. The dielectric properties of these spinel cobaltites were examined in low magnetic fields ranging from 0 to 10 mT. Using the Maxwell–Wagner model, the study demonstrates that the transport properties of spinel cobaltites can be modulated by an external magnetic field. Dielectric plots of various magnetic spinel cobaltites showed reduced resistance in the presence of a magnetic field, underscoring the significant impact of magnetic fields on the transport properties of these materials. The research also highlights the crucial role of interconnected grains and grain boundary effects on the transport mechanisms. This study provides valuable insights into the tunable transport properties of spinel cobaltites, potentially leading to advancements in their application in magnetic and dielectric devices.