Ab initio Study on Spectral Properties of Charge-Compensated Ce3+ in NaF

作者：Ma, Nai-yu; Yang, Feng; Shen, Xian-chun; Huang, Yu-cheng; Ning, Li-xin^*

来源：Chinese Journal of Chemical Physics, 2014, 27(5): 512-518.

DOI：10.1063/1674-0068/27/05/512-518

• Ab initio calculation
• NaF:Ce3+
• Local structure
• Transition

We report an ab initio study of spectral properties of Ce3+ doped at Na+ site of the NaF crystal, with the charge imbalance compensated by two oxygen substitutions for fluoride (O-F') in the first coordination shell or two sodium vacancies (V-Na') in the second coordination sphere. Density functional theory calculations within the supercell model are first performed to optimize the local structures of the charge-compensated Ce3+, based on which Ce-centered embedded clusters are constructed and wave function-based CASSCF/CASPT2/RASSI-SO calculations are carried out to obtain the energies of 4f(1) and 5d(1) levels. By comparing the calculated 4f -> 45d transition energies with experimental excitation spectra at low temperatures, the lowest 4f -> 5d transition band peaked at 390 nm is assigned to the Ce3+ with charge compensation by two coordinating O-F' substitutions, rather than to the Ce3+ with compensation by two V-Na' vacancies, as proposed earlier. The electronic reason for the large redshift (by similar to 8000 cm(-1)) of the lowest 4f -> 5d transition as induced by the two nearby OF' substitutions is analyzed in terms of the changes in the centroid shift and crystal-field splitting.

• 出版日期2014-10
• 单位安徽师范大学