Phase analysis of Fe₃O₄ nanoparticles produced by electrical explosion of iron wire

The experimental platform for electrical explosion of wire was built and iron wire was electrically exploded in air to produce metal nanoparticles. The total energy deposited in the wire was estimated by time integration using the product of voltage and current waveforms measured by voltage divider and Rogowski coil, respectively. The light emission from the plasma was recorded by photoelectric detector. The composition and morphology of the electrical explosion product were tested by the high-multiple microscope, scanning electronic microscope (SEM), transmission electron microscopy (TEM), the energy dispersive spectroscope (EDS) and X-ray diffractometry (XRD) to analyze the products phase characteristics. The results show that during the process of electrical explosion, when iron wire goes from liquid phase to gas phase, current hardly flows through the wire and load voltage of wire approaches the initial charge voltage of capacitor due to rapid increase of wire resistance. With energy deposited into wire, arc plasma is formed in the chamber. Meanwhile, current can flow through the low resistance arc plasma, which leads to voltage as well as current waveforms evolving into underdamped sinusoidal waveforms. The product of iron wire electrical explosion is composed of Fe3O4 nanoparticles and most of them are in good spherical shape. The particle size ranges mainly from 30 to 60 nm and obeys the log-normal distribution.