Publications

Strain fields around high-energy ion tracks in α-quartz

Follstaedt, D.M.; Norman, A.K.; Doyle, Barney L.; McDaniel, F.D.

Transmission electron microscopy has been used to image the tracks of high-energy 197Au +26 (374 MeV) and 127I +18 (241 MeV) ions incident in a nonchanneling direction through a prethinned specimen of hexagonal α-quartz (SiO 2). These ions have high electronic stopping powers in quartz, 24 and 19 keV/nm, respectively, which are sufficient to produce a disordered latent track. When the tracks are imaged with diffraction contrast using several different reciprocal lattice vectors, they exhibit a radial strain extending outward from their disordered centerline approximately 16 nm into the crystalline surroundings. The images are consistent with a radial strain field with cylindrical symmetry around the amorphous track, like that found in models developed to account for the lateral expansion of amorphous SiO 2 films produced by irradiation with high-energy ions. These findings provide an experimental basis for increased confidence in such modeling. © 2006 American Institute of Physics.