Pyrochlore A₂B₂O₇ compounds are of important candidate host materials proposed for the stabilization and immobilization of high-level radioactive nuclear wastes forms and have received much radiation damage studies in recent years mainly by heavy ions. In this report, we present the results from polycrystalline Lu₂Ti₂O₇ pyrochlore compounds induced by light ion irradiations (400 keV Ne). Light ions such as neon produce primarily simple interstitial-vacancy Frenkel pairs (mono point defects) while heavy ions such as krypton or xenon produce significantly higher densities of point defects and defect aggregates that may have different influences on damage evolution, defect accumulation, and ultimately amorphization.  Order-to-disorder (O-D) and crystalline-to-amorphous (C-A) structural transformations are characterized using grazing incidence X-ray diffraction (GIXRD) and cross-sectional transmission electron microscopy (TEM). Results will be discussed in the context of crystal chemistry.

Y. H. Li, Materials Science & Technology Division, Los Alamos National Laboratory, United States
Y. Q. Wang*, Materials Science & Technology Division, Los Alamos National Laboratory, United States
J. A. Valdez, Materials Science & Technology Division, Los Alamos National Laboratory, United States
J. H. Won, Materials Science & Technology Division, Los Alamos National Laboratory, United States
M. Tang, Materials Science & Technology Division, Los Alamos National Laboratory, United States
K. E. Sickafus, Materials Science & Technology Division, Los Alamos National Laboratory, United States

*presenting author