Synthesis of nanocrystalline yttrium disilicate powder by a sol-gel method

In the present work a new route for the synthesis Of alpha -Y2Si2O7 is reported. The method consists in the gelation of an acid solution composed by Y(NO3)(3) and tetraethylorthosilicate (TEOS) in the adequate molar ratio to form a precusor complex gel containing the Y3+ and Si4+ cations in the 1:1 ratio, which yields the stoichiometric alpha -Y2Si2O7 after calcining. The nanosize powder Of Y2Si2O7 obtained at 1060 degreesC was characterised by XRD and TEM. The conditions and main parameters such as temperature, pH or time for the hydrolysis of the Y(NO3)(3)/TEOS solution in HCl medium was investigated and optimised to obtain the precursor gel which was analysed by DTA and TGA. (C) 2001 Elsevier Science B.V. All rights reserved.