Abstract
AbstractA transmission electron microscope investigation was made of zirconolites and perovskites irradiated to amorphization with 1 MeV krypton ions using the HVEM-Tandem Facility at Argonne National Laboratory. Three specimens were examined - a prototype zirconolite CaZrTi2O7, a gadolinium doped zirconolite Ca0.75Gd0.50Zr0.75Ti2O7and a uranium doped zirconolite Ca0.75U0.50Zr0.75Ti2O7. The critical amorphization dose Dc was determined at several temperatures between 20K to 675K. Dc was inversely proportional with temperature. For example, pure zirconolite requiring 10x the dose for amorphization at 475K compared with gadolinium zirconolite. Using an Arrhenius plot, the activation energy Ea for annealing in these compounds was found to be 0.129 eV and 0.067 eV respectively. The greater ease of amorphization for the gadolinium sample is probably a reflection of this element’s large cross section for interaction with heavy ions. Uranium zirconolite was very susceptible to damage and amorphised under 4 keV argon ions during the preparation of microscope specimens. In each sample, zirconolite coexisted with minor perovskite, reduced rutile (Magneli phases) and zirconia. These phases were more resistant to ion irradiation than zirconolite. Even for high gadolinium loadings, perovskite (Ca0.8Gd0.2TiO3) was 3-4 times more stable to ion irradiation than the surrounding zirconolite crystals.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
