Cores and halos of uranium-ion tracks in LiF

The nanometric cores of tracks produced by high-energy heavy ions in {100} LiF have been revealed for the first time by high-resolution scanning electron microscopy. The observations have been made on samples irradiated with 10.0 MeV/A U-238 ions (ion linear energy transfer similar to 30 keV/nm), and subsequently etched for 2-60 s in a 48% HF:glacial CH3COOH:FeF3 solution. The track core, having a mean diameter of 12.0 +/- 4.3 nm, is a highly reactive region, indicating the importance of a radiolytically decomposed zone. Etching of the surrounding track halo, a strained LiF crystal, is controlled by both radiation effects and surface energies of crystal faces. (C) 2003 Elsevier B.V. All rights reserved.