Energy Levels of Pr3+ in LaF3

Abstract

The absorption and fluorescence spectra of Pr3+(4f2) in LaF3 have been investigated in the spectral region 4000 to 60 000 Å. From the present study and previously published data, all of the 2J+1 Stark components of the 3H4,5,6, 3F2,3,4, 1G4, 1D2, 3P0,2, levels are identified. By means of a least-squares method, we have calculated the Slater and spin—orbit parameters that give a theoretical free-ion spectrum in close agreement with the observed spectrum of Pr3+(4f2) in LaF3 crystals. When the electrostatic interaction between 4f2 and 5d2 electronic configurations is taken into account, the average deviation between the calculated and the observed spectrum is 58 cm−1. The values of the parameters giving the best fit are F2=312.7 cm−1, F4=50.99 cm−1, F6=4.778 cm−1, and ζ=757.0 cm−1.