Effect of swift heavy ion irradiation in pyrochlores

A summary of the results on the radiation stability of pyrochlores (Gd2Zr2O7, Nd2Zr2O7, Gd2Ti2O7) in the electronic stopping regime is given. X-ray diffraction and Raman spectroscopy show a transformation from the ordered pyrochlores (Fd3m) to the anion deficient fluorite (Fm3m) structure in Gd2Zr2O7 or amorphization in Nd2Zr2O7. The track diameter, crystallite size and progression in structural modifications have been monitored. It is found that radiation stability of these pyrochlores depends on the energy to form cation antisites and delocalized anion vacancies. This in turn is correlated to the radius ratio of A-B cations. This criterion for evaluating radiation resistance of pyrochlores has important implications in the field of inert matrix fuels. (C) 2008 Elsevier B.V. All rights reserved.