LUMINESCENCE AND ENERGY-TRANSFER PHENOMENA OF SEVERAL RARE-EARTH IONSIN THE CAAL2B2O7

The luminescence properties of Ce3+, Gd3+, and Tb3+ have been investig ated in the compound CaAl2B2O7. The single excitation band peaking at about 320 nm and single emission band peaking at about 384 nm for Ce3, without the characteristic doublet, are attributed to the extensive crystal-field splitting of 4f ground state. The emission of Gd3+ consi sts of well-known sharp lines and two weak bands around 319.5 and 325 nm. These bands are due to the coupling of Gd3+ with BO33- groups. The green emission of Tb3+ is considerably sensitized by Ce3+. Energy tra nsfer from Ce3+ to Tb3+ in CaAl2B2O7 is efficient. (C) 1997 Elsevier S cience Ltd.