Synthesis and structural characterization of a series of lanthanide stannate pyrochlores

A simple hydrothermal method has been employed to prepare a series of lanthanide stannate pyrochlores Ln(2)Sn(2)O(7) (Ln = Y, La, Pr-Yb) at a relatively low temperature of less than 200 C successfully. On the basis of structural characterizations by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) absorption spectroscopy and Raman spectroscopy, it Was found that the positions of hands in vibrational spectra are sensitive to the ionic radius of Ln(3+), and the linear relationship can be seen between the frequency of Sn-O stretching mode and the lanthanide ionic radius in IR spectrum, as well as the frequency of O-Sn-O bending mode and the lanthanide ionic radius in Raman spectrum. (C) 2008 Elsevier Ltd. All rights reserved.