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

In the present work a new route for the synthesis of α-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 α-Y2Si2O7 after calcining. The nanosize powder of Y2Si2O7 obtained at 1060°C 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.