ANALYSIS OF THE ENERGY-LEVEL SCHEME OF ND3+ IN NDOBR

A detailed analysis of the energy level scheme of the Nd3+ ion with th e 4f(3) electron configuration is described in the NdOBr matrix. 93 St ark levels were deduced from the optical absorption spectra recorded a t the UV, visible and NIR spectral ranges at selected temperatures fro m 9 to 300 K. The experimental level scheme was simulated with a pheno menological model with 19 parameters accounting simultaneously for the free ion and crystal field effects. The results of the simulation sho wed increasing covalence and decreasing crystal field effect from NdOF to NdOBr.