Production of nanopowders of oxides by means of fiber and pulse‐periodical CO₂ lasers

Abstract

The results of investigation of YSZ, Nd:Y2O3, Al2O3 nanopowder production by laser evaporation of oxide targets in a gas current are reported in present paper. For this purpose we used the pulse‐periodical CO2 laser and the continuous fiber ytterbium laser with 550 W and 600 W radiation mean power accordingly. The powders obtained by these lasers, consisted of weakly agglomerated spherical nanopartices (≥ 99 wt%), and ≤ 1 wt% of micron sized particles (drops and target fragments). Nanoparticles from various oxides produced by CO2 laser in atmospheric pressure air had close average sizes (10÷16 nm). The productivity of nanopowder synthesis by CO2 laser from YSZ 1%Nd:Y2O3, 1%Nd:Y2O3, Al2O3, and CeGdO was 23 g/hour, 29 g/hour, 24 g/hour and 80 g/hour, respectively. Unlike CO2 laser the deep melting mode is realized during evaporation of 1%Nd:Y2O3 and Al2O3 targets by fiber laser. The crater depth increases up to 300–1000 μm in this mode. As a result, the target surface became very irregular and productivity of nanopowder synthesis was less, than in the case of CO2 laser. To reduce the effect of deep melting the evaporation of a target has been investigated experimentally and theoretically. As a result of our investigations we have obtained 1%Nd:Y2O3 nanopowder with specific surface of 70 m2/g and productivity of 23 g/hour at air pressure 70 kPa. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Comparative study of Ho:Y2O3 and Ho:Y3Al5O12 transparent ceramics produced from laser-ablated nanoparticles

“…The ceramic samples have been fabricated at the Institute of Electrophysics UrB RAS (Ekaterinburg, Russia) using nano-sized particles synthesized by laser ablation [30]. The solid targets for ablation were prepared from commercial Ho2O3 and Y2O3 oxide powders mixed in the proportion of (Ho0.01Y0.99)2O3 and commercial Al2O3 powder.…”

Yb3+:(LuxY1−x)2O3 mixed sesquioxide ceramics for laser applications. Part I: Fabrication, microstructure and spectroscopy

“…The obtained powder targets were ablated in air flow of atmospheric pressure using a pulseperiodical carbon dioxide laser "LAERT" [ [21], [22]]. The main experimental parameters were as follows: pulse energy -0.9 J, pulse duration -330 μs, pulse repetition rate -500 Hz, peak power -7 kW, average power -450 W. The laser beam was focused into 0.75 mm × 0.9 mm-sized elliptical spot by a KCl lens with a power density of 1.3 MW/cm 2 .…”

Thermo-Optical Studies of Laser Ceramics

“…In Russia, there are several scientific groups involved in the development and production of laser ceramics, including Yb:YAG ceramics. We also tested the ceramics manufactured at the Institute of Electrophysics of the Ural Branch of the Russian Academy of Sciences and the Ural Federal University (Yekaterinburg, Russia), according to the original method, with the nanopowders obtained by laser ablation [ 98 ].…”