Controlled formation of chain aggregates from very small metal oxide particles

Described are performance characteristics of a flame aerosol generator that produces aggregates of metal oxide particles in high concentration. Operating modes can be selected to generate predominantly cluster-shaped or linear chain aggregates from iron pentacarbonyl, consisting of up to 200 spherical primary particles of constant density. Primary particle diameters are log-normally distributed with medians between 0.02 and 0.08 micrometer and sigma g congruent to 1.5, depending on flame's temperature, length, turbidity and carbonyl vapor concentration.