The c-axis and a-axis single crystals of a -Al2O3 implanted with 1 ×1017/cm2 of 171keV Y ions
and 9×1017/cm2 of 158keV Pt ions
respectively
have been investigated. The implantation was carried out at room temperature by using a MEVVA machine. Annealing was performed isothermally in air ambient at temperature in the range from 500℃ to 1050℃. The rutherford backscattering spectrometry and channeling of 2.4MeV He+ was used to study the depth distribution of lattice damage and implants. The microhardness and resistivity of the implanted layer were also measured. Results on structural changes were interpreted on the basis of the physical property measurements. The precipitates of implanted Pt were examined by XRD.