Growth, Structure, and Spectroscopic Characteristics of the Nd3+:LiGd(WO4)2 Crystal

The Nd3+:LiGd(WO4)(2) crystal with dimensions of 25mm x 28mm x 16mm was grown by the top-seeded solution growth method from the 60 mol% Li2W2O7 flux. LiGd(WO4)(2) crystallizes in the tetragonal system with. space group I4(1)/a (C-4h(6)) and cell parameters: a = 5.1986 and c = 11.2652 angstrom. The hardness is about 5.0 Mohs' scale. The specific heat is 0.40 J.g(-1).K-1 at 50 degrees C. The thermal expansion coefficients for a- and c-axes are 1.314 x 10(-5) and 2.052 x 10(-5) K-1, respectively. The room-temperature polarized absorption and emission spectra and the fluorescence decay curve was measured. The parameters of oscillator strengths, the spontaneous transition probabilities,,the. fluorescence branching ratios, the radiative lifetimes, and the emission cross sections have been investigated based on Judd-Ofelt theory and Fuchtbauer-Ladenburg method. The absorption cross-section is 5.19 x 10(-20) cm(2) at 805 nm for pi-polarization and its line width is 15 nm; the emission cross section is 1.726 x 10(-19) cm(2) at 1060.5 nm for pi-polarization. The fluorescence and radiative lifetimes are 86 and 158 mu s, respectively. The fluorescence quantum efficiency is 54.43%.