SPECTROSCOPY OF LIYF4 - EU3+ SINGLE-CRYSTALS

Polarised absorption and laser-induced fluorescence spectra of LiYF 4:Eu3+ were recorded at liquid-nitrogen temperature in the visible spectral range. Transitions with pure electric dipole, pure magnetic dipole and mixed dipolar character have been observed. Spectroscopic assignments to the energy levels are made on the basis of the observed energies, polarisation characteristics of the spectral lines and electric and magnetic dipole selection rules relevant to the S4 point group. 37 Stark components belonging to ten multiplets of Eu3+ have been established. Free-ion and crystal-field parameters have been obtained. Simulation of the crystal-field energy levels has been attempted with and without J-J mixing effects using intermediate-coupling wavefunctions.