Growth habits and characterization of Sr3NbGa3Si2O14 crystal

Ordered piezoelectric Sr3NbGa3Si2O14 (SNGS) single crystal with langasite family structure has been successfully grown with clear facet using Czochralski technique. The growth habit of SNGS crystal is revealed and discussed in detail. It is shown that the crystal is easily grown along 〈1 0 0〉 direction, and {1 0 0}, {0 0 1} plus {3 0 2} faces are strongly exposed as facets. Detailed X-ray powder diffraction (XRPD) patterns and indices calculated and observed for the crystal are given. The lattice parameters calculated from the XRPD data are a=8.28626±0.000911Å, c=5.07998±0.000481Å, V=301.8Å3 and the density is 4.6456 kg/m3. The density measured for SNGS crystal by Archimedes method is 4.6834 kg/m3. Etching experiments have been performed on {1 1 0}, {0 1 0} and {0 0 1} faces to observe the etch patterns. The transmittance spectra from 200 to 3000 nm have been measured and the absorption edge is determined to be 268 nm.