Study of the effect of irradiation with Fe7+ions on the structural properties of thin TiO2 foils

Abstract

Thin foils based on the TiO2 phase of brookite, 620 nm thick, were obtained by magnetron sputtering. The samples were irradiated at the DC-60 heavy ion accelerator of the Astana branch of the Institute of Nuclear Physics with Fe7+ ions with an energy of 85 MeV with a fluence of 1 × 1011 to 1 × 1014 ions cm−2. The dependences of the change in the concentration of defects in the structure of thin films on the radiation dose are established. It has been established that an increase in the irradiation fluence of up to 1014 ions cm−2, characteristic of the formation of defect overlap regions, leads to a sharp decrease in the degree of crystallinity and an increase in the lattice parameters. That is caused by the formation of a large number of disorder regions and displaced atoms in the structure, which migrate along the crystal lattice to additional distortions and voltages, with the subsequent formation of hillocks.