Further experiments on the solid state isotopic exchange model for the thermal annealing of Szilard-Chalmers recoiled species

Abstract

By investigating the thermal annealing of atoms which suffered Szilard-Chalmers recoil in double complexes like cis and trans-[Co en 2(NO 2) 2][Co EDTA]. nH 2O it had been found that the isochronal annealing curves of 60Co recoil species at cationic and anionic sites have the same structure and that the retentions at cationic sites are linearly correlated with those at anionic sites. The slope of the straight line represents the ratio r between the annealing probabilities at the two lattice sites. It was also ascertained that r depends on the kind of atmosphere in which the annealing is carried out. Because of the relevance of this finding for the solid state isotopic exchange model for the annealing reactions of recoil species, we studied the phenomenon in another double complex, cis-[Co en 2(NO 2)CNS] [Co EDTA]. 2H 2O, in order to ascertain the reproducibility of r values in different experiments carried out under constant conditions and to confirm the effect of the atmosphere composition on the r values. The reproducibility at constant experimental conditions was found satisfactory, and the dependence of r value on the experimental annealing and irradiation conditions was confirmed. The results are discussed in terms of the above mentioned model for the thermal annealing reactions of atom suffering Szilard-Chalmers recoil.