Crystal-field analysis of Eu3+ in Lu2O3

Low temperature (7 K) absorption spectra of polycrystalline sintered ceramic Lu2O3:Eu3+ were recorded between 3950 and 50000 cm(-1). There are two different intrinsic Eu3+ sites, C-2 and S-6 (C-3i), in this host. A total of 105 crystalfield (CF) energy levels were assigned and fitted to a semiempirical Hamiltonian representing the combined free-ion (FI) and CF interactions for a 46 ion in the C-2 symmetry site. 10 FI and 14 CF parameters were varied simultaneously in the least square adjustments yielding an rms deviation between the calculated and experimental levels of 15 cm(-1). The CF strength parameter, S, obtained from calculated B-q(k) parameters is larger for LU2O3 when compared to the Y2O3 host, which is in accordance with the smaller ionic radius of the Lu3+ ion. The CF splittings of the F-7(1), and D-5(1) levels were also determined experimentally for the Eu3+ ion in the centrosymmetric S-6 site and the value of the second-rank B-0(2) CF parameter was calculated.