Damage accumulation in Sm2Ti2O7 single crystals irradiated with Au2? ions at 170, 300 and 700 K was studied by Rutherford backscattering spectrometry using a 2.0 MeV He? beam along the channeling direction. The relative disorder on the Sm sublattice follows a nonlinear dependence on ion fluence. The nonlinear behavior is described well by a disorder accumulation model that indicates a predominant role of a defect-stimulated amorphization process. The critical dose for amorphization at 300 K is ~0.14 dpa, which is in good agreement with in-situ transmission electron microscopy results for polycrystalline Sm2Ti2O7 irradiated with 600 keV Bi? ions and with Gd2Ti2O7 doped with 244Cm. Despite the six orders of magnitude difference in damage rates, the good agreement between the amorphization doses in Sm2Ti2O7 at 300 K and 244Cm-doped Gd2Ti2O7 at 340 K indicates that damage accumulation at these temperatures is relatively independent of dose rate.
Revised: September 19, 2018 |
Published: June 1, 2004
Citation
Zhang Y., V. Shutthanandan, R. Devanathan, S. Thevuthasan, D.E. McCready, J.S. Young, and G. Balakrishnan, et al. 2004.Damage Accumulation and Amorphization in Samarium Titanate Pyrochlore.Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms 218.PNNL-SA-39437.doi:10.1016/j.nimb.2003.12.003