Amorphization due to electronic energy deposition in defective strontium titanate

The synergistic interaction of electronic energy loss by ions with ion-induced defects created by elastic nuclear scattering processes has been investigated for single crystal SrTiO₃. An initial pre-damaged defect state corresponding to a relative disorder level of 0.10–0.15 sensitizes the SrTiO₃ to amorphous track formation along the ion path of 12 and 20 MeV Ti, 21 MeV Cl and 21 MeV Ni ions, where Ti, Cl and Ni ions otherwise do not produce amorphous or damage tracks in pristine SrTiO₃. The electronic stopping power threshold for amorphous ion track formation is found to be 6.7 keV/nm for the pre-damaged defect state studied in this work. These results suggest the possibility of selectively producing nanometer scale, amorphous ion tracks in thin films of epitaxial SrTiO₃.