Luminescence and excitation spectra of U3+doped RbY2Cl7single crystals

Uranium(3+) doped single crystals of RbY2Cl7 with a uranium concentration of 0.05% and 0.2% were grown by the Bridgman-Stockbarger method using RbU2Cl7 as the doping substance. Polished plates of ca. 5 mm in diameter were used for measurements of luminescence and excitation spectra. Since the U3+ ions occupy two somewhat different site symmetries, a splitting of all observed f-f bands was observed. The analysis of the spectra enabled definitively an assignment of 2 crystal field bands for both site symmetries as well as the total crystal field splitting of the ground level, equal to 473 cm(-1) and 567 cm(-1) for the first and second site symmetry, respectively.