Raman and IR studies of TaWO5.5, ASbWO6 (A = K, Rb, Cs, Tl), and ASbWO6·H2O (A = H, NH4, Li, Na) pyrochlore oxides

• Published in: Journal of Raman spectroscopy 2011-03, Vol.42 (3), p.529-533
• Main Authors: Ma̧czka, M., Knyazev, A. V., Kuznetsova, N. Yu, Ptak, M., Macalik, L.
• Format: Article
• Language: English
• Subjects: Band spectra; Bands; defect pyrochlores; Disorders; Infrared; Infrared radiation; infrared spectra; Oxides; Pyrochlores; Raman scattering; Spectra
• ISSN: 0377-0486; 1097-4555; 1097-4555
• DOI: 10.1002/jrs.2735

Raman and infrared (IR) spectra of defect pyrochlores TaWO5.5, NH4SbWO6·H2O, HSbWO6·H2O, LiSbWO6·H2O, NaSbWO6·H2O, KSbWO6, RbSbWO6, CsSbWO6, and TlSbWO6 were measured. The obtained spectra are discussed using the factor group approach for the cubic Fd‐3m space group, and assignment of bands to respective motions of atoms is proposed. Our results show that the phonon properties of the pyrochlores are strongly affected by disorder, and therefore Raman and IR spectroscopies are very useful tools in studying disorder in this family of compounds. In particular, our studies have shown that in these ionic conductors disorder at sites occupied by NH$_{4}^{+}$, H+, or alkali‐metal ions decreases with increasing size and mass of these ions. Copyright © 2010 John Wiley & Sons, Ltd. Raman and IR spectra of defect pyrochlores are discussed. Our results show that Raman and IR spectroscopies are very useful tools in studying the disorder in this family of compounds. In particular, our studies show that the disorder at the sites occupied by NH$_{4}^{+}$, H+, or alkali‐metal ions decreases with increasing size and mass of these ions.