PROCESS FOR OBTAINING MAGNETIC NANOPARTICLES BY LASER ABLATION

摘要

The invention relates to a process for obtaining magnetic nanoparticles for devices storing information of ultra-high density. According to the invention, the process consists in irradiating a target (5) of ferromagnetic metal with a beam (2) coming from an ultra-fast laser (1) which operates in picosecond pulses, the target (5) being placed inside an enclosure (4) with controlled atmosphere, the laser beam (2) being focused on the target using a lens (3), where, in order to reach the energy density needed for the ablation of the material thereof, a laser ablation plasma (7) is formed, the target (5) being moved during irradiation, and the target ablation being performed in the presence of an indifferent gas coming from a cylinder (15), the nanoparticles produced being collected on a filter or on the surface of a sublayer on which another thin layer (6) may be previously deposited, the nanoparticles obtained being collected and partially oxidized in the presence of oxygen, in a superficial layer, so as the nanoparticles get the core-shell structure, with the core consisting of ferromagnetic metal and the shell consisting of the oxide of the said metal.