OPTICAL-SPECTRA OF TRIPLY-CHARGED RARE-EARTH IONS IN POLYCRYSTALLINE CORUNDUM

Solid samples of polycrystalline corundum alpha-Al2O3 activated by tri ply-charged rare-earth ions RE3+ (R=Eu3+, Er3+, Pr3+) were synthesized by the sol-gel technology. Characteristic narrow-line optical absorpt ion and luminescence spectra produced by intraconfigurational 4f-4f tr ansitions in RE3+ ions have been measured. RE3+ ions have been establi shed to form one dominant type of optical centers in the corundum matr ix, and the energy diagram of Eu3+ and Er3+ Stark levels in corundum h as been determined. (C) 1998 American Institute of Physics. [S1063-783 4(98)01208-8].