The crystal of Sr6YbSc(BO3)6 has been grown by the top-seeded solution growth (TSSG) method from a Li6B4O9 flux. The spectroscopic characterizations of the crystal have been investigated at room temperature. The absorption cross-section is 1.31×10-20 cm2 at 977 nm with a FWHM of 9 nm, which is very suitable for LD pumping. Using the method of reciprocity, the emission cross-section at wavelength 1020 nm is calculated as 0.85×10-20 cm2, and the fluorescence lifetime is measured to be 160 μs, indicating the Sr6YbSc(BO3)6 crystal is a promising stoichio- metric laser material.
Nd3+ doped KLa(MoO4)2 single crystal with the size up to φ25 × 40 mm3 was grown by the Czochralski technique. The absorption and luminescence spectra of trivalent neodymium in KLa(MoO4)2 crystal were investigated at room temperature. The absorption and emission cross sections are 3.02 × 10–20 cm2 at 808 nm and 20.01 × 10–20 cm2 at 1061 nm, respectively. The fluo- rescence lifetime is 164 ìs at room temperature.
The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20 cm2 and ?6 = 3.1189×10-20 cm2; the radiative lifetime is 123 μs; the quantum efficiency is equal to 64.55%; and β1 = 0.5498, β2 = 0.3943, β3 = 0.0551 and β4 = 0.0027 for the fluorescence branch ratios.
The crystal of the title compound Sr6Gd0.61Sc1.39(BO3)6 (Mr = 1037.00) was grown by Czochralski method. It crystallizes in trigonal, space group 3Rwith a = 12.415(2), c = 9.274(2) ? Z = 3, V = 1238.0(4) 3, Dc = 4.173 g/cm3, l(MoKa) = 0.71073 ? m = 22.278 mm-1, F(000) = 1411, S = 1.213, the final R = 0.0577 and wR = 0.1414 for 401 observed reflections with I>2s(I). In the structure Gd(1)O6 (Gd(1) = Gd0.46 + Sc0.54) and Gd(2)O6 (Gd(2)= Gd0.15 + Sc0.85) are alternately stacked between the planar triangular BO3 groups to form chains extending along the trigonal axis. These chains are connected through the 9-coordinate Sr atoms.
The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.
