Crystal-field analysis of Er3+ ions in yttrium aluminium borate (YAB) single crystals

Crystal-field energy levels of Er3+ ions doped in YAB single crystals were fitted to the parameters of semi empirical Hamiltonian including J-mixing. A simulation of the energy level scheme is carried out. The effective Hamiltonian includes elementary interactions such as columbic, spin-orbit, two- and three-body interactions. The crystal-field effect is introduced through the six non-zero crystal-field parameters allowed by D3 symmetry site occupied by the rare earth. Very satisfactory correlations were obtained between calculated and experimental levels, with root mean square deviation (r.m.s.) of 15.5 cm−1. These results are compared with those reported for Nd3+ and Dy3+ ions in the same host and with Er3+ ions in other hosts. The concordance between the crystal-field strength parameters indicates the consistence of our analyses. The calculated wave functions of the system are used to predict the magnetic g-factors of the 4I15/2 ground state.