Growth and properties of new nonlinear LiKB4O7 single crystals

Successful growth of new nonlinear LiKB4O7 single crystals by the Czochralsky technique are reported. Peculiarities of thermal expansion and its influence on the post-growth cooling have been analyzed. The LiKB4O7 single crystal is optically biaxial, na>nc>nb, and the optical axes are located in plane (0 0 1); bisector of acute angle between these (ϕ∼56°) coincides with crystallographic axis [0 1 0]. Coefficients of thermal expansion at 293 K: αa=16×10-6K-1, αb=11×10-6K-1, αc=12×10-6 K-1 and β=39×10-6K-1. The Moose hardness is equal to 5. Second harmonic generation has been observed in LiKB4O7 single crystal.