Laser heated pedestal growth and optical characterization of CaTa2O6 single crystal fiber

Transparent, colorless 30 mm long, (705 - 11)mum diameter CaTa2O6 single crystal fibers with a cubic crystalline structure (Pm3) were grown by the Laser Heated Pedestal Growth technique. The lattice parameter was a = (7.757 plus/minus 0.002)A obtained from the Rietveld refinement. The fiber growth direction was determined as [1 0 1] by X-ray diffraction. The growth temperature was (2040 plus/minus 100)DGC and the axial temperature gradient measured at the crystallization interface was (7.5 plus/minus 1.0) x 103 DGC/cm. The fiber/pedestal-pulling ratio was equal to 1.20. Undoped samples were characterized by optical microscopy, X-ray diffraction patterns, infrared transmission and Raman scattering. The structural and spectroscopic results indicate that this crystal may have potential as a host for active ions such as neodymium and erbium which have interesting emissions in the near-infrared region.