Gamma ray induced decomposition of double nitrates of lanthanum and cerium with some mono and bivalent cations in solid state

Abstract

Gamma ray induced decomposition of two series of double nitrates; 2M INO 3⋯Ln(NO 3) 3⋯ x H 2O (where M I = NH + 4, Na +, K +, Rb +, Cs +; Ln III = La 3+, Ce 3+ and x = 2 or 4) and 3M II(NO 3) 2·2Ln III(NO 3) 3⋯24H 2O (where M II = Mg 2+, Co 2+, Zn 2+; Ln III = La 3+, Ce 3+) has been studied in solid state over a wide absorbed dose range at room temperature. G(NO − 2) values have been found to depend on the absorbed dose and the nature of cation in both the series of double salts. Radiation sensitivity of lanthanum double nitrates with monovalent cations at an absorbed dose of 158 kGy follows the order NH + 4 < Rb + ≅ Cs + < Na + < K + and those of cerium NH + 4 < Rb + <Na + <K +. G(NO − 2) values of lanthanum double nitrates with bivalent cations at an absorbed dose of 206 kGy range from 0.22 to 1.05 and follow the order Zn 2+ < Co 2+ < Mg 2+ while for cerium salts are in the range 0.62–0.91 in the order Zn 2+ ≅ Co 2+ < Mg 2+. In fact double nitrates of cerium with Zn 2+ and Co 2+ exhibit almost similar G(NO − 2) values over the dose range 5–640 kGy. X-ray powder diffraction patterns of the irradiated Mg-La double salt indicate the possibility of structural phase transformation at certain doses.