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

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 divided by 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 mu m 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 m(2)/g and productivity of 23 g/hour at air pressure 70 kPa. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim