EFFECT OF MODIFIER IONS ON THE COVALENCY OF ND3+ IONS IN CADMIUM BORATE GLASSES

An investigation of the optical absorption spectra of 1 mol% Nd3+ ions in cadmium berate glass and effect of network modifiers, alkali ions, Li, Na and K is presented. Special emphasis is laid on the position, intensity parameters, Omega(lambda), lambda = 2,4,6, of the I-4(9/2) - -> F-4(7/2), S-4(3/2), and hypersensitive I-4(9/2) --> (4)G(5/2) trans itions. The effect of covalency of the rare earth ion sites on the tra nsition probabilities was estimated from the variation of the profiles of the absorption spectra in terms of the nephelauxetic effect. The v ariation of intensity ratio and the Judd-Ofelt parameter, Omega(2), wi th composition depended on the Nd-O covalency. (C) 1998 Elsevier Scien ce B.V. All rights reserved.