OPTICAL-SPECTRA AND CRYSTAL-FIELD CALCULATIONS OF ND3-TYPE YMO4 LASERHOSTS (M = V, P, AS)( DOPED ZIRCON)

Low temperature absorption spectra of Nd3+ doped YVO4, YPO4 and YAsO4 single crystals, grown by the flux method, are reported. A simulation of the energy level scheme is carried out. The effective Hamiltonian i ncludes elementary interactions such as coulombic, spin-orbit, two- an d three-body interactions. The crystal field effect is introduced thro ugh the five non-zero crystal field parameters allowed by the D-2d sym metry site occupied by the rare earth. A simulation is performed on th e 96 (102, 90) experimental energy levels of YVO4, (YPO4, YAsO4) with a good rms standard deviation of 16.2 (15.4, 15.7) cm(-1). It is notew orthy that the energy level scheme of YAsO4 is reported for the first time. The wave functions of the systems are used for the calculation o f the magnetic factor g. These factors are in good agreement with the values deduced from EPR measurements on the Nd3+ lowest level I-4(9)/( 2). The crystal field parameters are also compared to the a priori par ameters calculated using the simple overlap model and the correlated c rystal field strength is also analysed.