Damage evolution and thermal recovery of Au2? irradiated samarium titanate pyrochlore (Sm2TiO7) single crystals were studied by Rutherford backscattering spectroscopy and nuclear reaction analysis. The damage accumulation follows a nonlinear dependence on dose that is well described by a disorder accumulation model, which indicates a predominant role of defect-stimulated amorphization processes. The critical dose for amorphization at 170 and 300 K is ~0.14 dpa, and a higher dose of ~0.22 dpa is observed for irradiation at 700 K, which agrees with previous in-situ transmission electron microscopy (TEM) data for polycrystalline Sm2Ti2O7. Annealing in an 18O environment reveals a damage recovery stage at ~850 K that coincides with a significant increase in 18O exchange due to oxygen vacancy mobility. This thermal recovery stage is also consistent with the critical temperature for amorphization measured by in-situ TEM in polycrystalline samples.
Revised: May 27, 2004 |
Published: April 5, 2004
Citation
Zhang Y., V. Shutthanandan, S. Thevuthasan, D.E. McCready, J.S. Young, R. Devanathan, and J.D. Andreasen, et al. 2004.Damage Evolution and Annealing of Au-Irradiated Samarium Titanate Pyrochlore. In Radiation Effects and Ion Beam Processing of Materials, Materials Research Society Symposium Proceedings, held December 1-5, 2003, Boston, Massachusetts, edited by LM Wang, R Fromknecht, LL Snead, DF Downey and H Takahashi, 792, 69-74, Paper No. R2.4. Warrendale, Pennsylvania:Materials Research Society.PNNL-SA-40141.