Structural, optical, and electrical response of MgO nanoparticles synthesized via co-precipitation method for electronic applications
摘要
Magnesium oxide nanoparticles (MgO NPs) were synthesized via co-precipitation method using magnesium nitrate hexahydrate and sodium hydroxide at room temperature. To enhance crystallinity, the nanoparticles were annealed at 300 °C. UV–Visible spectroscopy revealed a broad absorption band between 240 and 280 nm, while FTIR analysis confirmed the Mg–O bond stretching vibration at 546 cm−1. X-ray diffraction (XRD) showed a single-phase face-centered cubic (FCC) periclase structure, with an average crystallite size of approximately 25 nm, calculated using the Scherrer equation. Field emission scanning electron microscopy (FESEM) images revealed uniform nanoparticles, and energy-dispersive X-ray spectroscopy (EDX) confirmed an elemental composition of about 44.6% magnesium and 55.4% oxygen. Dielectric properties were investigated using a Hioki 3533 Hi-Tester LCR meter over a frequency range of 10–2 to 105 Hz. The dielectric loss tangent was higher at low frequencies, indicating space charge polarization and interfacial effects. Capacitance, dielectric permittivity, and dielectric loss increased with pellet thickness and temperature but decreased with increasing frequency. Dielectric modulus analysis suggested non-Debye relaxation behavior, reflecting improved charge mobility. Electrical conductivity increased with pellet thickness and temperature, attributed to enhanced carrier mobility. Thickness-induced percolation facilitated the formation of conductive pathways, thereby improving dielectric performance. Impedance measurements, supported by Nyquist and Cole–Cole plots, showed that pellet thickness (1–5 mm) and temperature (25–100 °C) decreased bulk resistance, confirming improved ionic conductivity, interfacial polarization, and thermally activated hopping conduction, making the material suitable for electrical and electronic applications.