Radiation Damage and Recovery of Neutron-irradiated Al_2O_3 Crystal

Al2O3 single crystal was neutron-irradiated up to a dose of 5.74×1018 cm-2.The radiation damage and recovery of neutron-irradiated was studied by means of spectrophotometer.The results indicated that the irradiation generated large amount of optically detectable defects such as anion vacancies(primarily F and F+ center),anion divacancies(F2) and some higher order defects.Through isochronal annealing,the low order defects such as anion vacancies may recover under the low temperature,the high order defects are strengthened and the new absorb peaks which meant the higher order defects appeare with annealing.However,when the annealing temperature is up to 1000 ℃,all the defects are recovered.