ChemInform Abstract: Synthesis, X‐Ray Rietveld Analysis, Infrared and Moessbauer Spectroscopy of R₂FeSbO₇ (R³⁺: Y, Dy, Gd, Bi) Pyrochlore Solid Solution.

Abstract

Synthesis, X-Ray Rietveld Analysis, Infrared and Moessbauer Spectroscopy of R 2FeSbO7 (R 3+ : Y, Dy, Gd, Bi) Pyrochlore Solid Solution. -Ln2FeSbO7 (Ln: Y, Dy, Gd) and Bi 2FeSbO7 are prepared by calcination of stoichiometric mixtures of Ln2O3 (Bi2O3), Fe2O3, and Sb2O3 in air (alumina crucible, 1100-1150 C, 24 h), the Bi variant by staged heating from 700 to 1000 C. The polycrystalline powders show particle sizes of 30-40 nm. Rietveld refinement of powder XRD data show that the compounds crystallize in the cubic space group Fd3m. The bands at 642 and 490 cm -1 observed in the FT-IR spectra of Y2FeSbO7 are ascribed to the stretching vibrations of the smallest inter-atomic bond M(Fe/Sb)-O in MO 6 octahedra and the Y-O' bond, respectively. Moessbauer spectra are discussed. -(JANA*, Y. M.; HALDER, P.; BISWAS, A. A.; ROYCHOWDHURY, A.; DAS, D.; DEY, S.; KUMAR, S.; J. Alloys Compd. 656 (2016) 226-236, http://dx.