Raman scattering and X-ray diffraction on YBiTi2O7 prepared at low temperature

The conditions of preparation of a pure YBiTi2O7 phase by sol-gel were optimised. A single phase was obtained at temperature as low as 800 degrees C when triethanolamine/diethanolamine was used as additional ligands. The expected composition was confirmed by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). YBiTi2O7 exhibits the pyrochlore structure with a unit-cell parameter of 10.2117(5) angstrom. This structure was confirmed by Raman spectroscopy, which revealed a shift of the main E, mode towards lower wavenumbers when bismuth is introduced in the structure. Broad bands were observed for all the recorded spectra, which characterise rather a disorder due to bismuth III cations in the structure than an effect of particle size. This study confirmed the possibility to lower the temperature of preparation of pyrochlores containing bismuth, which could be of interest as photocatalyst for the decomposition of organic and toxic materials. Copyright (C) 2008 John Wiley & Sons, Ltd.