External magnetic field effects on the characteristics of cobalt nanoparticles prepared by pulsed laser ablation

Effects of DC magnetic field in the range of 0-180 mT on the properties of cobalt oxide nanoparticles (Co3O4 NPs) synthesized by pulse laser ablation method in distilled water has been investigated. Ablation was carried out in the presence of permanent magnets with variable strengths. Significant blue shift in excitonic absorption peaks of produced nanoparticles show that with increasing the magnetic field strength during the ablation process, size of nanoparticles was decreased noticeably. This result was confirmed by SEM and TEM images. XRD pattern show that with applying external magnetic field we may have crystalline structure nanoparticles while in the absence of external magnetic field, only amorphous phase of Co nanoparticles was produced. FTIR spectra present the metal oxygen vibration at 614 and 668 cm(-1), revealed octahedral and tetrahedral site of cobalt oxide system. In overall it can be concluded that external magnetic field is a strong tool to control the properties of laser ablation produced ferromagnetic nanoparticles.

Automated summary

The study found that a DC magnetic field in the range of 0-180 mT has significant effects on the properties of cobalt oxide nanoparticles synthesized by pulse laser ablation in distilled water. Increasing the magnetic field strength during the ablation process resulted in a noticeable decrease in the size of the nanoparticles, leading to a shift in their excitonic absorption peaks. By applying an external magnetic field, crystalline structure nanoparticles were obtained, while in the absence of an external magnetic field, only amorphous phase nanoparticles were produced. The results suggest that an external magnetic field is a strong tool for controlling the properties of ferromagnetic nanoparticles produced by laser ablation.