γ-Fe2O3 nanoparticles prepared by laser ablation of a tiny wire

Abstract

A new method of preparing nanoparticles by pulsed laser ablation of a tiny wire is reported. A Nd : YAG pulsed laser with a wavelength of 1064 nm was used to ablate a 0.5-mm-diameter iron wire in a sealed chamber in a flowing mixed gas of N2, O2, and air to generate γ-Fe2O3 nanoparticles. In the meantime, a bulk Fe sample was ablated in the same chamber with the same laser processing parameters in order to compare the effect of the bulk sizes on the production rates and the sizes of the nanoparticles. The experimental results demonstrated that the production rate of nanoparticles prepared by laser ablation of tiny wires was about eight times that of laser ablation of bulk targets with the same composition, while the sizes of the nanoparticles were basically the same. With a higher power density and/or smaller diameters of the metal wires, it is possible to obtain smaller sizes of the nanoparticles with higher production rates.