Journal of Applied Crystallography

Volume 35, Part 5 (October 2002)

research papers

J. Appl. Cryst. (2002). 35, 577-580 [ doi:10.1107/S0021889802010555 ]

X-ray structure determination of the rare earth oxides (Er_1-uGd_u)₂O₃ applying the Rietveld method

Z. Heiba, H. Okuyucu and Y. S. Hascicek

Abstract: Nanosized polycrystalline samples of (Er_1-uGd_u)₂O₃ (0 [less-than or equal to] u 1.0) were synthesized by a sol-gel technique. X-ray diffraction data were collected and the crystal structures were refined by the Rietveld method. All samples are found to have the same crystal system and formed solid solutions over the whole range of u. The Er³⁺ and Gd³⁺ ions were randomly distributed over two cationic sites, 8b and 24d, in the space group Ia $\bar{3}$ (206) in all refined structures. The lattice parameter was found to vary non-linearly with the composition (u). The average microstrain and average crystallite size have been calculated from the Williamson-Hall plots for each sample. The average size ranges from 50 to 70 nm, and the microstrain from 0.4 to 1.7%.

Keywords: rare earth oxides; solid solutions; microstrain; crystallite size; Rietveld refinement; lattice parameter variation; sol-gel.

Journal of Applied Crystallography

Volume 35, Part 5 (October 2002)

research papers

X-ray structure determination of the rare earth oxides (Er1-uGdu)2O3 applying the Rietveld method

Z. Heiba, H. Okuyucu and Y. S. Hascicek

X-ray structure determination of the rare earth oxides (Er_1-uGd_u)₂O₃ applying the Rietveld method