Particulate Filtering Upon Pulsed Femtosecond Laser Deposition

摘要

Pulsed femtosecond laser deposition has been shown to suffer from a severe particulate problem. However, in contrast to pulsed nanosecond laser deposition, particulates are not ejected as molten droplets, but as condensed clusters formed in the highly dense ablation plasma. In order to utilize the advantages of pulsed ultrashort laser deposition, three strategies for particulate avoidance are experimentally demonstrated: electrostatic filtering, scattering at a background gas, and magnetic filtering. Ultrathin layers prepared by these three techniques are characterized by scanning and transmission electron microscopy and promise for future developments are outlined.