INFLUENCE OF GAMMA-IRRADIATION ON THE THERMAL-DECOMPOSITION OF (BAC2O4+CUO) MIXTURE

Influence of gamma-irradiation, 0.1-0.75 MGy on the thermal decomposit ion of (BaC2O4+CuO, 10 mol%) mixture has been studied between the temp erature range 678-718 K. It is evident from 'alpha-t' plots that decom position of both unirradiated and irradiated mixtures follows: (i) ini tial gas evolution (initial puff of gas), (ii) acceleratory and (iii) decay periods. Irradiation promotes the initial gas evolution (alpha(i )), decreases the fractional decomposition (alpha), the effect bring h igher at lower doses, without altering the nature of the isotherms. Bu t these effects increase with increasing radiation dose. Analysis of t he kinetic data in the light of theories of various kinetic models are found to be well fitted to Prout-Tompkins, Avrami-Erofeyev and contra cting square mechanisms. It is found that irradiation diminishes the r are of reaction of both the periods and decreases the energy of activa tion of the acceleratory stage without affecting the same in the decay period. Plausible mechanism of decomposition and the effect of gamma- irradiation thereon has been discussed in detail.