A novel technique to grow stoichiometric lithium niobate single crystal

Stoichiometric LiNbO ₃ crystal has received much attention because of its excellent properties. Here we reported a novel growth technique to grow near-stoichiometric LiNbO ₃ single crystal. This technique also uses a double-chamber crucible including a growth chamber and a melt supply chamber, here melt supply is executed by lowering down a Pt-made mould in the melt supply chamber to push the melt to the growth chamber, not by adding raw material powders to the melt supply chamber. The near-stoichiometric LiNbO ₃ crystal grown by this novel technique was clear without inclusion, free of crack and in light yellow. The composition of as-grown crystal and its homogeneity were characterized by the optical methods of measurement of UV absorption edge and the Li ₂O composition in the whole crystal thus characterized was 49.774±0.016 mol%. The test by Raman band wide method and Curie temperature method also verified the homogeneous composition. Etching morphologies of the crystals shown that they were single domain. The novel growth technique is promising for batch production of stoichiometric lithium niobate single crystal and also shown the potential application for other incongruent melting crystals.