Authors: A V Eremin E V Gurentsov K Yu Priemchenko
Publish Date: 2013/06/01
Volume: 15, Issue: 6, Pages: 1737-
Abstract
In this article the process of nanoparticle formation under the condensation of highly supersaturated atomic vapor produced by the photodissociation of metalbearing compounds was investigated The iron nanoparticles were synthesized by Kr–F laser pulse photolysis of FeCO5 The measurements of an optical density of condensed phase were performed using a laser light extinction at a wavelength 633 nm The particle size during their formation process was measured by a twocolor timeresolved laserinduced incandescence The final iron particle sizes and their structure were analyzed by a transmission electron microscopy It has been shown that the process of iron particle formation in the investigated conditions could be divided onto three stages the fast nucleation of iron atoms during 1–2 μs the surface growth of particles up to the sizes of 1–6 nm with increasing volume fraction of condensed phase during 100–250 μs and the relatively slow particle coagulation up to the final sizes of 5–9 nm The effective rate constants of iron clusters and particle growth were extracted using laser light extinction measurements The essential role of the reactions of iron clusters and particles with the parental FeCO5 molecules was established The kinetic mechanism of iron nanoparticle growth induced by photodissociation of FeCO5 at room temperature based on obtained experimental results and known literature data has been suggested The results obtained could be used for the developments of methods of synthesis of catalysts magnetic nanopowders and others nanomaterials at room temperature Besides that the presented experimental data could be useful for the validation of kinetic models of gasphase condensation of supersaturated vapor of solids
Keywords: