Cation antisite disorder in uranium-doped gadolinium zirconate pyrochlores

The incorporation of uranium into gadolinium zirconate (Gd2Zr2O7) is investigated by synchrotron X-ray powder diffraction and X-ray absorption near-edge structure (XANES) spectroscopy. The results suggest that the uranium cation is largely located on the pyrochlore B-site instead of the targeted A-site. Cation disorder in Gd2Zr2O7 and U-doped Gd2Zr2O7 is investigated by positron annihilation lifetime spectroscopy (PALS) which demonstrates the absence of cation vacancies in these systems. This work provides direct evidence for cation antisite (A- and B-site mixing) disorder in U-doped and off-stoichiometric Gd2Zr2O7 pyrochlore. © 2014, Elsevier B.V.

Keywords

Uranium, X-ray diffraction, Cations, Pyrochlore, Zirconates, Spectroscopy

Citation

Gregg, D. J., Zhang, Z., Thorogood, G. J., Kennedy, B. J., Kimpton, J. A., Griffiths, G. J., Guagliaro, P. R. Lumpkin, G. R., & Vance, E. R. (2014). Cation antisite disorder in uranium-doped gadolinium zirconate pyrochlores. Journal of Nuclear Materials, 452(1–3), 474-478. doi:10.1016/j.jnucmat.2014.05.021