Synthesis of ultrafine gadolinium oxide powder by mechanochemical processing

The synthesis of ultrafine Gd2O3 powder by mechanochemical reaction and subsequent heat treatment via the reaction 2GdCl3+3CaO→Gd2O3+3CaCl2 was studied using X-ray diffraction, transmission electron microscopy and differential thermal analysis. Dried GdCl3 and CaO powders were mechanically milled and subsequently annealed at various temperatures. During milling, GdOCl nanoparticles of ∝16 nm in size were formed by a solid-state displacement reaction. Heat treatment of the as-milled powder at 700 C resulted in the formation of monoclinic Gd2O3 crystallites of ∝100 nm having a thin platelet morphology. (orig.)