Energy Levels and Crystal-Field Splittings of Nd3+ in Yttrium Oxide

Abstract

Studies of the absorption and fluorescence spectra of Nd³⁺ in yttrium oxide are reported in this paper. The three Racah parameters E^1,2,3 and the spin—orbit parameter ζ giving the best over‐all agreement between the observed and calculated spectrum are E¹=4853.9, E²=24.20, E³=471.87, and ζ=877.59 cm⁻¹. The Stark splittings of the four levels ⁴I_9/2, ⁴I_11/2, ⁴I_13/2, and ⁴I_15/2 are used in a first‐order perturbation calculation to determine the crystal‐field parameters for Nd³⁺ in the C₂ sites of the Y₂O₃ lattice. The parameters are used to calculate the Stark splitting of 13 excited levels, and the results are compared with experimentally observed values. For 64 Stark components, the calculation predicts the splitting with an average of about 15 cm⁻¹. For the components of the ²H_11/2 and ²G_7/2 levels, very large discrepancies are present.