Energy levels and crystal field calculations of Nd3+ in the REBMO5 phases (RE=rare earth, M=Ge, Si)

Abstract

The optical properties of mixed oxides from the RE2O3–B2O3–MO2 chemical system (RE=rare earth; M=Ge, Si) with general formula REBMO5 have been analyzed. The energy level scheme of the Nd3+ ion in the two structural types NdBGeO5 and NdBSiO5 have been deduced from the absorption and emission spectra recorded at different temperatures between 4.2 and 300 K. The simulation has been carried out on the 109 energy levels found for NdBGeO5 and 125 for NdBSiO5. The phenomenological crystal field parameters have been determined assuming a C2v point symmetry for the rare earth in NdBGeO5 and C2 or Cs in NdBSiO5. The r.m.s. standard deviation is 17.5 cm−1 for NdBGeO5 and 18.1 cm−1 for NdBSiO5, indicating a satisfying agreement between the calculated and experimental levels.