Growth, physicochemical and optical properties of LuYSGG garnet single crystal

We investigate the physical and chemical properties of a Lu1Y2Sc2Ga3O12 (LuYSGG) single crystal with high quality grown by the Czochralski (Cz) method. The XRC result shows the crystal has high crystalline quality and the lattice constant is calculated to be 12.4253 Å, and the lattice constant value could be adjusted by changing the ratio of Lu and Y. The dislocation density on the (111)-crystalline face is achieved to be about 200 cm-2. The Mohs hardness is obtained to be 6.86. The surface roughness (Ra) of the polished LuYSGG wafer is only 0.23 nm. The thermal expansion coefficient and the thermal conductivity are measured to be 8.5×10-6 K-1 and 4.79 W m-1 K-1, respectively, indicating the LuYSGG has better thermal properties. In addition, the Sellmeier equation is fitted by the measured refractive indices at a few distinct wavelengths using the method of minimum deviation angle, and the refractive index curve in the range of 400-3000 nm is displayed. The maximum phonon energy of LuYSGG crystal is determined to be 880.7 cm-1. All the obtained results can provide useful reference parameters for the further investigation of LuYSGG crystal as epitaxial magneto-optical thin film substrate and laser host.