Impact of Diverse Nanostructure Forms of NiCo₂O₄ Bulk Ceramics on Electrical Properties

Spinel NiCo₂O₄ is a promising material for electronic applications due to its tunable nanostructures and electrical properties. This study systematically investigates the effect of varying urea concentrations in the hydrothermal solution on the nanostructural evolution of NiCo₂O₄ (NCO) and its impact on electrical and dielectric properties. By varying urea content, distinct morphologies-including nanosheets, nanoleaves, and nanofibers-were obtained and characterized via XRD, XPS, and FE-SEM analysis. To evaluate the electrical characteristics, capacitance and conductance measurements were performed using an LCR Meter at room temperature over a frequency range of 100 Hz to 1 MHz. The results revealed negative capacitance at low frequencies, linked to polarization changes and minority charge carriers. Also, dielectric parameters were calculated from measured values, showing that nanoform variations influence conductivity trends. This study provides new insights into how nanoform variations in NiCo₂O₄, controlled by synthesis parameters, influence its dielectric behavior. The findings significantly contribute to the understanding of negative capacitance and the tunability of electrical properties in NCO, highlighting their potential for future electronic and dielectric applications.