Energy Levels and g Values of Some Rare Earth Crystals with f2 Configuration

Abstract

Abstract The energy levels of the rare earth ions in praseodymium ethyl sulfate, magnesium praseodymium nitrate, and thulium ethyl sulfate crystals are calculated by using an extended Hamiltonian for 4f2 configuration. The Hamiltonian includes two-body electrostatic interactions, spin-other-orbit interactions and two-body pseudomagnetic interactions as configuration-mixing parameters in addition to the Slater, spin-orbit coupling and crystal-field parameters. The standard deviations for praseodymium ethyl sulfate, magnesium praseodymium nitrate and thulium ethyl sulfate are respectively 10.1 cm−1 for 25 observed levels by using 13 parameters, 3.8 cm−1 for 12 observed levels by using 11 parameters, and 8.9 cm−1 for 32 observed levels by using 13 parameters. These results are consistent with similar studies of rare earth ions doped in the LaCl3 and LaF3 crystals. Most of the calculated Zeeman splitting factors (g value) parallel to the principal axis of the crystals also are in fairly good agreement with the experimental values. Some discussion is given as to the effect of configuration interactions, the accuracy of wave functions obtained and the discrepancy between some of the calculated g values and the observed ones.