Group-chain scheme analysis of the energy levels and magnetic properties of Er3+ in the LiYF4 crystal

Based on the analysis of group-chain scheme wavefunctions and the use of the constraint condition set down by the ratios of crystal-field parameters calculated by the point-charge model, the crystal-field-level fitting and the study of Zeeman interaction characterized by the g-factor in Er3+ : LiYF4 have been carried out, in which the Er3+ ions occupy positions with point symmetry S-4. The RMS of energy-level fitting is less than 8 cm(-1), and the corresponding wavefunctions of Stark sublevels are useful in the calculation of the g-factors of the ground and excited states. The calculated results agree well with the experiment and Confirm Karayianis' partial g-sum rule. The method proposed turned out to be effective in the study of not only the spectroscopic and laser properties but also the magnetic properties of ram-earth ions in crystals.