Characterization of cobalt oxide nanoparticles produced by laser ablation method: Effects of laser fluence

The role of laser fluence in producing cobalt oxide nanoparticles in distilled water by laser ablation method has been studied experimentally. Output of a pulsed Nd:YAG laser of 1064 nm wavelength and 7 ns pulse width with 10 Hz repetition rate was employed to irradiate a high purity cobalt bulk in distilled water. According to results, size of produced nanostructures as well as their oxidation was strongly under the influence of laser energy. Although a high purity Co bulk was used as the target of laser irradiation in the experiment but produced nanoparticles were mainly cobalt oxides. X ray diffraction pattern indicates that produced nanostructures are Co3O4. The excitonic absorption peak of Co3O4 nanoparticles was occurred in UV region. Results show that with increasing the fluence of laser pulse, size of nanoparticles was decreased while their aggregation was increased noticeably.