ABSORPTION AND FLUORESCENCE OF ER3-DOPED LIYF4 - MEASUREMENTS AND SIMULATION()

Er3+:LiYF4 single crystal has been studied by absorption and fluoresce nce spectroscopy in the IR-visible-UV (0-44000 cm(-1)) region from 4.2 K to room temperature. Polarized spectra were recorded in order to as sign numerous Stark levels of electronic transitions mentioned but not attributed before in the related literature and to discuss the irredu cible representations (irreps) of the I-4(15/2) sublevels. A parametri c hamiltonian, including free ion (E-nu, alpha, beta, gamma, T-lambda, zeta, M-k and P-i) and crystal field parameters (B-0(2), B-0(4), B-4( 4), B-0(6) and B-4(6)) in an approximate D-2d symmetry for the rare ea rth site in this scheelite type structure, was used to simulate 109 en ergy positions of the Er3+ ion with a r.m.s. standard deviation of 14. 6 cm(-1). A comparison with previously published results for Nd3+ in t he same matrix is done. (C) 1998 Elsevier Science S.A.