Synthesis of ultrafine Gd2O3 powder by mechanochemical reaction and subsequent calcination was studied using X-ray diffraction measurements, transmission electron microscopy, surface area measurements and thermal analysis. Dried GdCl3 and NaOH powders were mechanically milled together and subsequently calcined at various temperatures. A solid-state displacement reaction GdCl3 + 3NaOH --> Gd(OH)(3) + 3NaCl was induced during milling. Calcining of the as-milled powder at 500 degrees C led to the formation of Gd2O3 particles of similar to 1 mu m having a cubic structure. Adding sufficient amount of NaCl diluent in the starting powder resulted in the formation of ultrafine Gd2O3 particles of similar to 20 nm in size. (C) 1999 Acta Metallurgica Inc.
|Publication status||Published - 1999|