ION IRRADIATION DAMAGE IN ILMENITE AT 100 K

A natural single crystal of ilmenite (FeTiO3) was irradiated at 100 K with 200 keV Ar2+. Rutherford backscattering spectroscopy and ion chan neling with 2 MeV He+ ions were used to monitor damage accumulation in the surface region of the implanted crystal, At an irradiation fluenc e of 1 x 10(15) Ar2+/cm(2), considerable near-surface He+ ion dechanne ling was observed, to the extent that ion yield from a portion of the aligned crystal spectrum reached the yield level of a random spectrum. This observation suggests that the near-surface region of the crystal was amorphized by the implantation. Cross-sectional transmission elec tron microscopy and electron diffraction on this sample confirmed the presence of a 150 nm thick amorphous layer. These results are compared to similar investigations on geikielite (MgTiO3) and spinel (MgAl2O4) to explore factors that may influence radiation damage response in ox ides.