Atomic structure of ion tracks in Ceria

作者：Takaki S; Yasuda K^*; Yamamoto T; Matsumura S; Ishikawa N

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2014, 326: 140-144.

DOI：10.1016/j.nimb.2013.10.077

• Ceria
• Swift heavy ion
• Ion track
• TEM
• STEM

We have investigated atomic structure of ion tracks in CeO2 irradiated with 200 MeV Xe ions by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). TEM observations under inclined conditions showed continuous ion tracks with diffraction and structure factor contrast, and the decrease in the atomic density of the ion tracks was evaluated to be about 10%. High resolution STEM with high-angle annular dark-field (HAADF) technique showed that the crystal structure of the Ce cation column is retained at the core region of ion tracks, although the signal intensity of the Ce cation lattice is reduced over a region 4-5 nm in size. Annular bright field (ABF) STEM observation has detected that the 0 anion column is preferentially distorted at the core region of ion tracks within a diameter of 4 nm. The core region of ion track in CeO2 is determined to contain a high concentration of vacancies or small vacancy clusters and to generate interstitials in surrounding regions.

• 出版日期2014-5-1