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 degrees C in reducing atmosphere. The sintering behavior of Tb2O3 was studied under microwave heating up to 1780 degrees C. The microstructure of the powders and ceramics was investigated by scanning electron microscopy. Near full-density material was obtained at about 1620 degrees C. Further temperature increases causes a deterioration of the ceramics microstructure due to monoclinic Tb2O3 phase formation.