Porous track cores along wakes of swift Pb ions in LiF

Abstract

Continuous density decreases of ∼50% within 98μm long and 3.2nm wide cylindrical ion damage trails, latent ion tracks, created in a {100} LiF platelet by 2.31GeV Pb ions, have been measured by small-angle X-ray scattering. Structural alteration is attributed mainly to radiolytic decomposition of the crystal into Li atoms and fluorine molecules, and subsequent transport and release of the fluorine gas through the low-density tracks. Free volume and Li residues undoubtedly account for the observed enhanced etchability of the track-core region.