Synthesis and structural characterization of ultrafine terbium oxide powders

Glycine-nitrate self-propagating high-temperature synthesis was used to synthesize terbium oxide nanopowders whose phase transformations were investigated by methods of high-temperature differential scanning calorimetry, dilatometry, and X-ray diffraction analysis. The as-prepared powders consisting of Tb7O12 and Tb11O20 phases were converted to Tb2O3 after calcination at 600-800 °C in reducing atmosphere. The sintering behavior of Tb2O3 was studied under microwave heating up to 1780 °C. The microstructure of the powders and ceramics was investigated by scanning electron microscopy. Near full-density material was obtained at about 1620 °C. Further temperature increases causes a deterioration of the ceramics microstructure due to monoclinic Tb2O3 phase formation.