Electronic transitions, crystal field analysis and anomalous levels splittings in the optical spectrum of Pr3+ in La2O3 and Pr2O3

A complete account of the electronic transitions observed at 20 and 300 K for La2O3:Pr3+ (1%) and Pr2O3 in powder and single crystal form in the 4000-22 000 cm(-1) spectral range is reported. The electronic lines are accompanied by a number of vibronic sidebands [1]. At 20 K, 42 out of 61 symmetry levels are determined in the doped sample and 27 in the neat sample. A crystal field analysis is performed in the theoretical site symmetry C-3v With and without 4f(2)/4f 6p configuration interaction. The splittings of the D-1(2) (1), F-3(2) (3), and H-3(6) (2) levels are examined and discussed in parallel with a similar observation made previously on La2O3 :Eu3+ [2] The splitting is not observed on the crystal. A crystal field analysis is performed in a distorted C-1 symmetry affecting the (ff) and the (fp) crystal field parameters. (C) 1999 Elsevier Science B.V. All rights reserved.