D-D neutron and Cu-ion irradiation effects on structural and optical properties of single-crystal rutile TiO₂(001)

Single crystals rutile Ti0₂ with (001) orientation were irradiated with 2.5 MeV D-D neutrons and 80 keV Cu ions respectively. The structural and optical properties of the irradiated single crystals were investigated using positron annihilation technique and EXAFS. The results indicated that D-D neutron as well as Cu-ion irradiation has induced a great number of defects. The induced defects of D-D neutron irradiated rutile distribute coherently throughout the wafers while the maximum damage range is approximately at 425 nm for Cu-ion irradiated rutile. Contraction in cell volume and blue shift of absorption edge toward a higher energy in the ultraviolet-light region were also observed in neutron irradiated rutile, however, due to the Cu substitution for Ti in lattice, the results of cell volume and change in band gap are quite different from that of neutron irradiated ones. (authors)