INFLUENCE OF THE CRYSTALLOGRAPHIC ORIENTATION OF THE SURFACE ON DAMAGE AND CHEMICAL EFFECTS IN ION-IMPLANTED MGO

The influence of the crystallographic orientation of the surface on io n implantation damage was studied in MgO single crystals. For this pur pose, rare gas ions (150 keV-argon) or reactive ions (150 keV-niobium) were implanted at room temperature in (100) and (110) MgO surfaces at a fluence of 5.10(16) ions.cm(-2). With the mean of Rutherford Backsc attering Spectroscopy in channeling geometry (RBS-C), it is shown that the damage depends on the crystallographic orientation of the MgO sur face. The (100) irradiated surfaces exhibit a localized damage as pred icted by TRIM code calculations while in (100) MgO, the defects extend in depth. Chemical effects are also dependent on the crystallographic orientations of the implanted surfaces: the substitutional fraction o f the implanted niobium determined by RBS-C and the niobium binding en ergy estimated by XPS analysis are different in the (110) and (100) Mg O irradiated surfaces.