Growth, thermal and spectral properties of Er3+/Yb3+: Lu0.5Gd0.5VO4 mixed crystal

A high quality Er3+/Yb3+:Lu0.5Gd0.5VO4 crystal with dimensions of 20 × 24 × 28 mm3 has been grown successfully by the Czochralski method. The concentrations of Er3+ and Yb3+ in the Er3+/Yb3+: Lu0.5Gd0.5VO4 crystal were calculated to be about 0.95 mol% and 1.68 mol%, respectively. The XRD pattern of the crystal confirmed that it is isostructural with pure GdVO4 and LuVO4 single crystals. The thermal properties of the crystal were studied by analyzing specific heat, thermal expansion coefficients and thermal diffusivity. The spectroscopic characterizations of the crystal, including the polarized absorption spectra and fluorescence spectra were recorded at room temperature. Spectral parameters such as the intensity parameters (Ω2, Ω4 and Ω6), oscillator strengths, radiative transition probability and radiative lifetime of Er3+ were calculated by Judd-Ofelt theory. All the results suggest that Er3+/Yb3+: Lu0.5Gd0.5VO4 crystals can be an excellent candidate laser material.