[en] The gamma ray induced decomposition of double nitrates of Pr and Gd with Mg²⁺, Co²⁺ and Zn²⁺ has been studied over a wide absorbed dose range upto 640 kGy at room temperature. Also, the radiolytic decomposition of Nd, Sm and dy double nitrates with Mg²⁺ and Zn²⁺ has been investigated at an absorbed dose of 250 kGy. The G(NO₂^-) values depend on the absorbed dose, nature of the lanthanide ion and the bivalent outer cation. The G(NO₂^-) value for all the lanthanide double nitrates at an absorbed dose of 205 kGy follow the order Mg²⁺, Co²⁺>Zn²⁺. The double nitrates with Mg²⁺ exhibit G(No₂^-) values at same dose in the order Nd³⁺≅Gd³⁺>Sm³⁺>Pr³⁺>La³⁺>Dy³⁺>Ce³⁺ whereas for Zn²⁺ salts the order is changed to Ce³⁺>Nd³⁺≅Sm³⁺>Gd³⁺≅Pr³⁺>La³⁺. (author). 18 refs., 2 figs