Growth of Na modified potassium lithium niobate crystal by the Czochralski method

摘要

Transparent Na modified potassium lithium niobate (Na0.23K2.60Li1.82Nb5.35O15.70; NKLN) crystal was successively grown by the Czochralski method using RF induction heating from melt composition NaO:K2O : Li2O:Nb2O5 = 2:30:25:43 mol %. NKLN crystal showed a tetragonal tungsten bronze structure with lattice constants a = 12.5446 +/- 0.0010 Angstrom and c = 4.0129 +/- 0.0005 Angstrom at room temperature. The dielectric constant along the c-axis epsilon(33) showed a sharp maximum around 480 degreesC. Optical transmission edge was 370 nm and optical transmission spectra showed no absorption at wavelengths ranging from 380 to 800 nm. The structural and optical properties of NKLN were similar to those of the near stoichiometric KLN crystals. We believe that the growth of NKLN by the Czochralski method has an advantage for a large size and high-quality crystal. (C) 2004 Elsevier B.V. All rights reserved.