Analysis of the production and clusterization of iron atoms under pulsed laser photolysis of Fe(CO)$_5$

Atomic-resonance absorption spectroscopy is used to study the production and loss of iron atoms under dissociation of the Fe(CO)$_5$ vapor in a quartz reactor that is induced by the pulses of the KrF excimer laser. Iron atoms populate the ground state owing to the quenching of the excited states generated in the course of the laser photolysis and are detected using the resonance absorption at a wavelength of 385.99 nm. The effective quenching rates are in good agreement with the known rates of the quenching of metastable iron atoms by the Fe(CO)$_5$ molecules. It is demonstrated that a loss of iron atoms is related to the recombination with dimer and trimer formation and the secondary atomic reactions with the Fe(CO)$_5$, CO, and FeCO molecules. The rates of the main elementary reactions responsible for the loss of iron atoms are determined using the comparison of the experimental results and kinetic simulation data.