Precipitation of Tm2O3 nanopowders for application in reactive sintering of Tm:YAG

In this study thulium oxide powder has been prepared by the precipitation technique using several precipitating agents, i.e. ammonium carbonate, ammonium hydrogen carbonate and ammonia. The relation between precipitation parameters and the properties of thulium oxide nanopowders has been investigated. The morphology and physical properties of the fabricated Tm2O3 powders have been examined using a scanning electron microscope (SEM) and performing nitrogen sorption measurements (BET). Finally, commercially available alumina, yttria and precipitated Tm2O3 powders have been mixed and subsequently sintered for 6 h at 1830 °C. For comparison, ceramics with the same composition (2 at% Tm:YAG) have been prepared from commercial micrometric thulium oxide powder. The resultant ceramics have been studied in terms of their microstructure and optical transmittance. It has been found that the best homogeneity and transmittance has been obtained in the case of mixture with ammonia precipitated Tm2O3 powder.