Isothermal studies on gamma irradiated oxalates of yttrium and samarium

Abstract

The influence of γ-irradiation (0.01–1.0 MGy) on the isothermal decomposition of Y 2(C 2O 4) 3 and Sm 2(C 2O 4) 3 has been studied by gas evolution method between the temperature range 603–643 and 623–663 K respectively. The “ α- t” plots of both unirradiated and irradiated salts follow: (i) initial gas evolution, (ii) a short acceleratory period, and (iii) a long decay period. The data on all categories of samples are discussed in the light of various kinetic models for solid state reactions and are found to be well-fitted to Prout-Tompkins and Avrami-Erofeyev mechanisms. Results on unirradiated and irradiated, Y 2(C 2O 4) 3 are also well explained by contracting square relationship. The fractional decomposition, α is enhanced by irradiation, the effect being higher at higher doses in case of both the substances. Irradiation has marginal effect on the energy of activation of the acceleratory and decay periods in the case of Sm 2(C 2O 4) 3 but it reduces the same in the former stage and reverse phenomenon occurs in the latter period in the case of Y 2(C 2O 4) 3.