Optical spectra and crystal field calculations of doped Zircon-type laser hosts (, P, As)

Low temperature absorption spectra of doped , and single crystals, grown by the flux method, are reported. A simulation of the energy level scheme is carried out. The effective Hamiltonian includes elementary interactions such as coulombic, spin-orbit, two- and three-body interactions. The crystal field effect is introduced through the five non-zero crystal field parameters allowed by the symmetry site occupied by the rare earth. A simulation is performed on the 96 (102, 90) experimental energy levels of , ( , ) with a good rms standard deviation of 16.2 (15.4, 15.7) . It is noteworthy that the energy level scheme of is reported for the first time. The wave functions of the systems are used for the calculation of the magnetic factor g . These factors are in good agreement with the values deduced from EPR measurements on the lowest level . The crystal field parameters are also compared to the a priori parameters calculated using the simple overlap model and the correlated crystal field strength is also analysed.