Absorption spectrum analysis of uranium(III) formate

The absorption spectrum of a thin film of uranium(III) formate was measured at 4 and 300 K in the 4000-23 000 cm(-1) range. The energy levels of U3+ w ere assigned and fitted to a semiempirical Hamiltonian representing the com bined atomic and crystal-field interactions at the C-3v symmetry site. Ten energy level parameters were varied simultaneously in least-squares adjustm ents yielding a mean error of 23 cm(-1). The analysis enabled the determina tion of the crystal-held parameters and the assignment of 49 crystal-field levels. The calculated total splitting of the ground level is equal to 520 cm(-1). An analysis of the 5f(3)-->5f(3) band intensities based on the Judd -Ofelt theory is presented. (C) 2000 Elsevier Science S.A. All rights reser ved.