Thermal and radiation annealing in 131I--doped periodate crystals

Isothermal annealing at temperatures between 90 and 250 deg C and radiation annealing at 40, -76 and -196 deg C were studied in sodium periodate crystals doped by rapid crystallization and by spray techniques. The results showed the occurrence of transfer annealing because the dopant was converted to the oxidized forms of iodate and periodate depending on the treatment conditions. Similarities with the annealing behaviour of recoil species in neutron irradiated periodate systems are established and the Bellido and Wiles 'stepwise oxidation model' is used to explain the mechanism of the processes. (author)