Growth, structural and spectroscopic properties of Yb~(3+)-doped Li_(0.75)Gd_(0.75)Ba_(0.5)(MoO_4)_2 crystals

摘要

Yb-doped Li_(0.75)Gd_(0.75)Ba_(0.5)(MoO_4)_2 crystals were grown in air by the Top Seeded Solution Growth slow cooling method in a Li_2Mo_2O_7 flux. The single crystal X-ray diffraction analysis indicates the symmetry of monoclinic space group C2/c (No. 15), with lattice parameters a = 5.2355(3) A, b= 12.7396(8) A, c= 19.1626(11) A, β = 91.170(1)°, V= 1277.84(13) A~3 and Z=8, with one 8f site shared (0.725:0.06:0.215) by Gd~(3+), Yb~(3+) and Li~+ ions, respectively. The optical absorption and photoluminescence properties are described consistently with the anisotropic character of the monoclinic phase. The relative energies of the Yb~(3+) Stark levels have been determined, and in order to make a preliminary evaluation of its laser properties, values of the 300 K absorption and emission cross-sections have been derived.