Small angle x-ray scattering and electron microscopy of nanoparticles formed in an electrical arc

Abstract

Small Angle X-ray Scattering has been used to characterize nanoparticles generated by electrical arcing between metallic (AgSnO2) electrodes. The particles are found to have diameters between 30 and 40 nm and display smooth surfaces suggesting that they are either in liquid form or have solidified from the liquid state. Particles collected around the electrodes were analyzed by Transmission Electron Microscopy and were seen to be much larger than those seen in the SAXS measurement, to be spherical in form and composed of silver metal with irregular tin oxide particles deposited on their surface. Mixed metal nanoparticles can have important practical applications and the use of mixed sintered electrodes may be a direct method for their production

Particle Size Determination in Electrical Arcs Using X-Ray Scattering

“…In the example in figure 4a, the data could be fitted with a single family of nanoparticles, the measured radius of gyration (which for a log-normal particle size distribution corresponds to the mean diameter, assuming spherical particles) of which was found to be 33.6 nm. Overall in these measurements, the particle size was found to lie in the range from 30-40 nm for AgSnO 2 contacts [10]. Furthermore, the measured Porod factor was consistently found to be p=4, indicating that the particles had a smooth surface.…”

Influence of the reactive atmosphere on the formation of nanoparticles in the plasma plume induced by nanosecond pulsed laser irradiation of metallic targets at atmospheric pressure and high repetition rate

“…Third generation synchrotron radiation based Small Angle X-Ray Scattering (SAXS), allows in-situ probing for the presence of nano and mesoparticles to be done in complex media. In previous works, we have used SAXS to study particle size distributions in diffusion flames [13], microwave-generated fireballs [14], electrical arcs [15] and also in the plasma plume induced by nanosecond IR pulsed laser irradiation of titanium targets in air [16]. In the latter case, we showed the existence of at least two families of nanoparticles formed in the plasma plume.…”

Particle size determination in electrical arcs with Ag and AgSnO2 electrodes using X-ray scattering

“…The present experiment was performed on the SWING beamline of the Soleil synchrotron [5] dedicated to the SAXS technique.…”

“…Due to the arc temperature, T > 5000 K [2], the nanoparticles are probably formed on the periphery of the plasma where the temperature gradient allows condensation processes to occur. We have already reported our results for carbon, silver and silver-tinoxide (AgSnO 2 ) contacts [3][4][5][6] where we found that the size and character of the nanoparticles were a clear function of the materials. While AgSnO 2 electrodes have been found to generate particles with smooth surfaces in the range of 30-40 nm in diameter, pure silver contacts produce aggregated particles.…”