Structure of latent tracks in rutile single crystal of titanium dioxide induced by swift heavy ions

The structurally damaged zone in titanium dioxide rutile single crystal induced by MeV-order heavy ions was observed using high resolution electronic microscopy (HREM). Stressed regions as well as amorphous regions were identified in the damaged areas. Both stressed and amorphous regions were etched with hydrofluoric acid. The thermal spike model was used to calculate the track radii variation versus electron stopping power. When the calculated lattice temperature did not exceed the melting point of rutile titanium dioxide (2130 K), no structural change introduced by ions, such as 90 MeV Cl, was observed by HREM. It was found that the radius of the lattice temperature over the melting point corresponded closely to the radius of the stressed region. It was concluded that both stressed and amorphous regions are the result of quenching by molten titanium dioxide.