ZiSiO ₄ precursor in ZrO ₂-SiO ₂ dried gel inferred from the pair distribution function analysis data

High energy X-ray diffraction measurements of ZrSiO ₄ dried gel powders prepared from an equimolar solution of tetraethoxysilane and ZrO(NO ₃) ₂C 2H ₂O, have been carried out by using the synchrotron X-radiation source. Pair distribution function (PDF) for the ZrSiO4 gel samples prepared by refluxing shows the middle range ordering similar to crystallized zircon. High resolution electron microscopy reveals the unique nano-crystallites with a lattice fringe of about 0.33 nm periodicity. The present experimental condition for sample preparation with enough refluxing is substantially considered favourable for development of the structure in the middle range ordering together with nano-crystallite associated with zircon and this particular gel structure serves good environment for the low temperature formation of zircon.