SPECTROSCOPIC STUDIES AND CRYSTAL-FIELD ANALYSIS OF CM3+ AND GD3(+) IN LUPO4

Optical-absorption and laser-selective-excitation spectroscopy have be en used to investigate the electronic energy level structures of the a ctinide ion Cm3+ and the lanthanide ion Gd3+ in host crystals of LuPO4 . Crystal-field levels have been determined up to 35 000 and 37 000 cm (-1), respectively, for the principal D-2d symmetry substitutional sit e. These have been analyzed in terms of a parametric Hamiltonian and t he two systems compared. High-resolution fluorescence spectroscopy was used to resolve the ground-term splittings of Cm3+ and these are comp ared to the zero-field splittings measured in a previous EPR investiga tion. Some weaker fluorescence features also were observed, which are attributed to minor Cm3+ sites in the host lattice. Two-photon excitat ion was observed to the P-6(5/2) and P-6(7/2) multiplets of Gd3+.