High resolution Scanning Transmission Electron Microscopy (HRTEM) experiments were performed on Gd2Ti2O7 pyrochlores irradiated with 120-MeV U ions. A judicious choice of irradiation energy, sample preparation (using Focused Ion Beam) and analytical technique (HRTEM) allowed us to visualize the complete evolution of tracks from the surface of samples down to depths exceeding the projected range of irradiating ions. Such features as variation of track diameters, changes in track directions and discontinuous segments of tracks were clearly documented at various depths. By using two different STEM imaging modes: High- and Low-Angle Annular Dark Field imaging (HAADF and LAADF), it was possible to observe the layered structure of tracks composed of an amorphous core surrounded by a strained crystalline envelope.
Revised: April 30, 2013 |
Published: September 1, 2012
Citation
Jozwik Biala I., J.K. Jagielski, L. Thome, B.W. Arey, L. Kovarik, G. Sattonay, and A. Debelle, et al. 2012.HRTEM study of track evolution in 120-MeV U irradiated Gd2Ti2O7.Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms 286.PNNL-SA-81728.doi:10.1016/j.nimb.2011.12.040