Preparation and characterization of pyrochlore oxide Y2Ti2O7 nanocrystals via gel-combustion route

Pure-phase pyrochlore oxide Y2Ti2O7 nanocrystals with good dispersity were successfully synthesized via a glycine-nitrate gel-combustion approach. The preparation process and products were monitored and characterized by Fourier transform-infrared spectra, thermogravimetry-differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The detailed results suggested that the phase and nature of as-obtained products are highly dependent of the pH value of the precursor solution and the amount of glycine. Under the appropriate conditions that the pH value of the precursor is 2.0, the fuel-to-oxidant ratio is 2.0, and the calcination temperature is 800 °C, the as-prepared products are almost sphere-like or ellipsoid, exhibits perfect crystalline phase, good dispersity and a narrow particle distribution with an average size diameter of 20-30 nm. This soft-chemistry route can be also extended to prepare Y2Ti2O7-based functional nanomaterials and other pyrochlore-oxide nanocrystals.