Rate of F center formation in sapphire under low-energy low-fluence Ar+ irradiation

Ionoluminescence, optical absorption spectroscopy and Rutherford backscattering spectrometry channelling (RBS-C) have been used to study the rate of F center formation with fluence in 170 keV Ar+ irradiated single crystals of α-Al2O3 (sapphire) at room temperature. Implantation fluences range between 1013 cm−2 and 5×1014 cm−2. F center density (NF) has been found to display an initial rapid linear increase with Ar+ fluence followed by saturation to a maximum value of 1.74×1015 cm−2. Experimental results show a 1-1 correlation between radiation damage in the oxygen sublattice and F center density. This suggest F center kinetics in sapphire under low-energy low-fluence Ar irradiation is a direct consequence of dynamic competition between oxygen defect creation and recombination. An attempt has also been made to extend this discussion to F center kinetics in sapphire under swift heavy ion irradiation.