Growth and characterization of Nd,Yb – yttrium oxide nanopowders obtained by sol‐gel method

Nanopowders of Y₂O₃ pure, doped and codoped by Nd³⁺, Yb³⁺ were obtained by sol‐gel method. Solution with ethylene glycol was choosed as the proper solution where crystallites of powder with Nd and Yb dopants had the same size. Finally the one‐phased compounds of Y₂O₃ doped 0.5 at% Nd and 1, 2 or 4 at% Yb were obtained. Grain growth and their morphology were investigated in various temperature and time of heating. The changes of crystallite sizes and lattice constants in relation to the heating time and temperature for the composition Y₂O₃ doped 0.5 at% Nd and 2 at% Yb are presented. Y₂O₃ containing 0,5 at% of Nd exhibits intense luminescence bands centered at 920 nm, 1100 nm and 1360 nm whereas a single band at about 1020 nm appears in samples co‐doped with neodymium and ytterbium. Luminescence spectra recorded did not depend on the sample preparation procedure and size of grains. OH impurity affects critically the relaxation dynamics of luminescent ion in nanopowders. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)