Chemical effects in Zr- and Co-implanted sapphire

Sapphire samples were implanted with Zr and Co ions to a fluence of 5 × 1017 ions/cm2 in MEVVA implanter operated at 65 kV. XPS and RBS spectra were studied in the course of annealing within the temperature range of 200-1400 °C. It is concluded that Zr diffuses to the surface and forms ZrO2 precipitates, whereas Co migrates to the bulk and forms CoAl2O4 spinel which gives the crystal a bluish color. These changes are consistent with thermodynamical properties of the implanted ions.