Permalloy nanoparticles generated by laser ablation

We describe a new method for producing ultrafine magnetic particles that employs pulsed-laser particle ablation. Pulsed-laser radiation with wavelength of 248 nm was used to ablate 1 to 10 /spl mu/m diameter Permalloy microparticles under normal atmospheric conditions. The ejected nanoparticles were collected on silicon substrates for further analysis. Scanning electron micrographs of the samples were analyzed by computer aided image processing to determine the effect of laser fluence on the particle size distribution. Results showed that mean particle diameters were in the range from 60 to 90 nm, and that the particle size distributions were closely log-normal.