Transformation of the excitation energy in anion-defective corundum

Some regular features of the excitation energy transformation in anion-defective crystals of a-Al₂O₃ were analysed by the sub-nanosecond spectroscopic method. The samples were excited using synchrotron radiation and high-density pulsed electron beams. It was shown that much of the energy of the ionising radiation absorbed by the crystals was liberated as the luminescence of F⁺- and F-centres immediately at the moment of irradiation. Luminescence of F⁺-centres dominated in the nanosecond range, while luminescence of F-centres prevailed in the millisecond range. The excitation energy transformation processes and their kinetics were governed by the temperature, the concentration ratio of intrinsic defects in α-Al₂O₃ crystals, and the excitation density.