Comparative crystal free-ion energy level analysis of Nd 3+ (4f 3) ions in various oxygen co-ordinated systems

Abstract

We have reanalysed the crystal free-ion energy levels of Nd 3+(4f 3) ions in various oxygen co-ordinated systems. The best crystal free-ion energy level data available in the literature for the Nd 3+-doped systems of about 20 crystal hosts, namely, A-Nd 2O 3, Y 2O 3, YGaO 3, NdAlO 3, GdAlO 3, LiNbO 3, LiYO 2, NdNO 3·6H 2O, Ca(NbO 3) 2, Nd(NO 3) 3(DMSO) 4, La 2Be 2O 5, YVO 4, PbMoO 4, KY(MoO 4) 2, KY(WO 4) 2, LiGd(MoO 4) 2, CaAl 4O 7, Y 3Al 5O 12, Y 3Ga 5O 12 and Gd 3Ga 5O 12, were reanalysed in terms of a uniform free-ion model Hamiltonian. The free-ion model Hamiltonian consists of 20 free-ion parameters that are related to various interactions. The overall crystal free-ion parametrization of the experimental energy level data is reasonably good. The effects of the crystal hosts on the empirical parameters are examined. The nephelauxetic (β) and bonding (σ) parameters which are helpful to establish the trends of covalent or ionic interaction strengths in the Nd-doped systems were evaluated.