Single crystals of sapphire (α-Al2O3) implanted with 100keV
6×1016cm-2 (In+) or 360keV
1×1016cm2 (In+) have been studied. The implantation was carried out at room temperature but the annealing was performed isothermally in Ar or air atmosphere at temperature in the range from 600℃ to 1100℃ The Rutherford backscattering spectrometry and channeling of 2.4MeV He+ were used to observe the depth distribution of lattice damage and implants. The microhardness and resistivity of the implanted layer were investigated by means of the depth-sensing low-load indentation technique and the electrical conductivity measurement
respectively. Results on the structural changes are correlated with the measured changes of physical properties.