Method of producing single-polarized lithium tantalate crystal and crystal thereby obtained.

摘要

A method of producing a lithium-tantalate crystal comprising, at least subjecting a single-polarized lithium-tantalate crystal wherein an optical absorption coefficient at a wave number of 3480 cm<Sup>-1</Sup> is 0.3 cm<Sup>-1</Sup> or less to a heat treatment under a reducing atmosphere at a temperature of not lower than 250 °C and not higher than Curie temperature and a single-polarized lithium-tantalate crystal wherein an optical absorption coefficient at a wave number of 3480 cm<Sup>-1</Sup> is 0.3 cm<Sup>-1</Sup> or less and an electric conductivity is 1 x 10<Sup>-12</Sup> Ω<Sup>-1</Sup> · cm<Sup>-1</Sup> or more. There can be provided a method of producing a single-polarized lithium-tantalate crystal in a short time efficiently wherein the surface charge generated due to a pyroelectric property can be decayed quickly by improving the electric conductivity and a single-polarized lithium-tantalate crystal.