Dielectrics and Optical Properties of Green-Synthesized Fe₃O₄ Nanoparticles

Abstract

The magnetite (Fe3O4) nanoparticles have been green-synthesized using Moringa Oleifera extract (MO) with variations of 5, 10, 15, and 20 ml. The X-ray diffraction results confirmed that the microstructure of Fe3O4 nanoparticles is a cubic inverse spinel structure with an average particle size of 5.0-8.9 nm and lattice parameters in the range of 8.14-8.22 Å. The results of UV-VIS data presented that the absorption edges of Fe3O4 MO 5 ml were 193.4 nm and the band gap energy of Fe3O4-MO is in the range of 2.62-3.31 eV. Dielectric properties were measured using impedance spectroscopy in the frequency range of 10-900 kHz. The results of measurement were in the form of real dielectric (ε'), imaginary dielectric (ε''), and tangent loss (tan δ). The dielectric constant decreased with increasing frequency due to interfacial polarization. In addition, MO affected the dielectric properties of Fe3O4 nanoparticles. The dielectrics of green-synthesized Fe3O4 with various MO of 5, 10, 15, and 20 ml at a frequency of 10 kHz are 248.5, 276.9, 289.0, and 308.1, respectively. The results measurement of the dielectric properties showed the optimality of the green synthesized sample with MO concentrations of 10 and 15 ml with values ​​of 276.9 and 289.0 at a frequency of 10 kHz. So, green synthesis Fe3O4 magnetite nanoparticles are used for Surface Plasmon Resonance (SPR) and Electromagnetic Interference (EMI) Shielding because these two applications are dependent on frequency and dielectric constant.