Czochralski growth and characterization of Dy: La₃Ga_5.5Nb_0.5O₁₄single crystals

Dysprosium (Dy) doped La3Ga5.5Nb0.5O14 single crystals were grown by the traditional Czochralski method along z-axis. The structure of the crystal has been studied by X-ray powder diffraction method, and the unit-cell parameters are calculated to be a=8.22070 angstrom, c=5.12533 angstrom and V=299.965 angstrom(3). The segregation coefficient of Dy3+ in La3Ga5.5Nb0.5O14 Crystal was measured by X-ray fluorescence analysis. For 1 mol% doping level in the melt, the distribution coefficient of Dy3+ was determined to be 0.341 wt%. Specific heat, thermal expansion and transmission spectrum of Dy: La3Ga5.5Nb0.5O14 single crystals have been measured. The fluorescence spectra of Dy3+ : La3Ga5.5Nb0.5O14 crystals were measured at room temperature, and there were four emission transitions occurring at 479, 576, 662 and 754 nm, respectively. The fluorescent lifetimes measurement results show 1.0% Dy: La3Ga5.5Nb0.5O14 possesses shorter fluorescence decay time (303.4 mu s) than does 1.0%Dy:LGS (436.12 mu s). (c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim