Growth of potassium lithium niobate single-crystal fibers by the laser-heated pedestal growth method

Single crystals of potassium lithium niobate (KLN) are known as useful materials for electrooptic applications. KLN single-crystal fibers were grown by the halogen-lamp-assisted laser-heated pedestal growth (LHPG) method and both feed and seed ceramic rods consisting of 0.3K2O-0.17Li2O-0.53Nb2O5 were used for the growth. The growth conditions were a growth rate of 11 mm/h, a laser power of 1.9 W, and a halogen lamp power of 350 W for improvement of the thermal conditions around the crystallization point. The fibers obtained were approximately 0.70 mm in diameter. A transmission X-ray Laue photograph taken along the fiber growth axis indicated that the fibers were single crystals and their c-axis corresponded to the growth axis. Temperature dependence of dielectric constant and tan δ of fibers was measured. Curie temperature Tc of 420 °C of fibers grown by the LHPG method corresponded to that of feed rods.