(a) A sintered AuAg particle, (b) an unsintered  agglomerated AuAg particle and (c,d) XEDS maps of the elements, showing even alloying down to atomic level.

Nanoparticle composition

What is the composition of nanoparticles produced by spark ablation (SA)? This is a long-standing question for the community that use SA to produce bimetallic particles. The particles are formed from creating a high-voltage spark between two electrodes in a flowing inert gas. The electrodes can consist of one element each, or pre-formed alloy electrodes can be used.  

Analytical high-resolution transmission electron microscopy is one of the few methods that can give simultaneous information about particle size, degree of agglomeration and chemical composition of individual nanoparticles. There are, however, many other methods employed by e.g. the Aerosol community using collective properties of a large number of particles, and the results from these are compared to TEM-XEDS, to reveal any systematic discrepancies. The result show that TEM-XEDS is a reliable, reproducible method with high precision. The starting system was alloyed electrodes of two miscible metals; Ag and Au.  

This work has been performed by Linnea Jönsson/Maria Messing at Solid State Physics, in collaboration with ARTEMI in Lund, Ergonomics and Aerosol Technology, Occupational and Environmental Medicine, Chemical Engineering, Mathematical Statistics and in Hungary, Optics and Quantum electronics.

Publication:  L. Jönsson et al.  Journal of Aerosol Science 177 (2024) 106333