YAG and Y2O3 laser ceramics from nonagglomerated nanopowders

Undoped and Nd- or Yb-doped laser-grade yttrium aluminum garnet and (Y,La)(2)O-3 ceramics with a transmittance above 80% in the 1-mu m lasing region have been prepared by solid-state reactions using nonagglomerated Y2O3 and Al2O3 nanopowders. The Y2O3 nanopowders were prepared via laser evaporation, chemical precipitation from urea solutions, and grinding of commercially available Y2O3 in a purposedesigned laboratory-scale attritor at stirrer rotation rates of up to 1500 rpm. The YAG ceramics were prepared using commercially available Al2O3. After grinding, all of the powders had a particle size on the order of a hundred nanometers. Green compacts produced from the nanopowders were sintered in a vacuum furnace between 1615 and 1750A degrees C to give highly transparent ceramic samples.