Effect of cation size on the 60Co-gamma radiolytic decomposition of alkali and alkaline earth metal nitrates

60Co gamma (γ)-ray-induced decompositions of NaNO3 with 0.1-99.9 mol% of KNO3 and Sr(NO3)2 with 0.1-99.9 mol% of Ba(NO3)2 have been studied in the dose range of 60-500 kGy. Similar studies have been done for admixtures of other alkali metal nitrates. It has been observed by using various admixtures of alkali and alkaline earth metal nitrates that radiolytic decomposition of the nitrate is affected by all the cation additives at all the concentrations as well as by the absorbed dose. G(NO2−) values increase with the increase in the size of the substituting cation. The substitution of cation of host matrix by either a larger or a smaller one distorts the lattice facilitating the decomposition process, resulting in higher G-value. XRD patterns suggest the possibility of microcrystalline phase changes after γ-irradiation.