Ceracomp Co., Ltd.

Tae-Moo Hur

Ho-Yong Lee

Jong-Bong Lee

Sung-Yoon Chung

Nong-Moon Hwang

Suk-Joong L Kang

Doe-Yeon Kim

Byoung-Ki Lee

Dong-Ho Kim

Jong-Hong Lee

Jao-Suk Kim

Jae-Suk Kim

By controlling the average size of matrix grains of polycrystalline bodies to more than a critical size at which an abnormal, exaggerated or discontinuous grain growth ends, and less than twice the critical size, large single crystals enough for practical use may be made even without occurring abnormal grain growth in polycrystalline bodies only through a heat treatment process without using a melting process and a special apparatus, thereby allowing the mass production of the large single crystals at low costs with high reproduction possibility.

Method for solid-state single crystal growth

An effective, simple and low-cost a method for growing single crystals of perovskite oxideshaving primary and secondary abnormal grain growths according to temperature condition higher than a determined temperature or an atmosphere of heat treatment, involves a perovskite seed single crystal being adjoined to a polycrystal of perovskite oxides and heating the adjoined combination whereby the seed single crystal grows into the polycrystal at the interface therebetween repressing secondary abnormal grain growths inside the polycrystal. 1) The composition ratio of the polycrystal is controlled and/or the specific component(s) of the polycrystal is(are) added in an excess amount compared to the amount of the component(s) of the original composition of the polycrystal, 2) the heating is performed in the temperature range which is over primary abnormal grain growths completion temperature and below secondary abnormal grain growths activation temperature, whereby the seed single crystal grows continuously.

Method for single crystal growth of perovskite oxides

The invention relates to a method for growing single crystals of barium titanate &lsqb;BaTiO &rsqb; and barium titanate solid solutions &lsqb;(Ba M )(Ti N )O &rsqb;. This invention is directed to a method for growing single crystals of barium titanate or barium titanate solid solutions showing the primary and secondary abnormal grain growths with increasing temperature higher than the liquid formation temperature, characterized by comprising the step for a few secondary abnormal grains to continue to grow at a temperature slightly below the critical temperature where the secondary abnormal grain growth starts to occur. The method for growing single crystals of barium titanate or barium titanate solid solutions according to this invention has the advantage of providing an effective low cost in manufacturing process for single crystals by using a conventional heat-treatment process without the need of special equipment. The method for growing single crystals of barium titanate and barium titanate solid solutions according to this invention is also applicable to other material systems showing abnormal grain growth behavior.

Method for single crystal growth of barium titanate and barium titanate solid solution

The invention relates to a method for growing single crystals of barium titanate &lsqb;BaTiO &rsqb; and barium titanate solid solutions &lsqb;(Ba M )(Ti N )O &rsqb;. This invention is directed to a method for growing single crystals of barium titanate or barium titanate solid solutions showing the primary and secondary abnormal grain growths with increasing temperature higher than the liquid formation temperature, characterized by comprising the step for a few secondary abnormal grains to continue to grow at a temperature slightly below the critical temperature where the secondary abnormal grain growth starts to occur. The method for growing single crystals of barium titanate or barium titanate solid solutions according to this invention has an advantage to provide an effective low cost in manufacturing process for single crystals by using usual heat-treatment process without special equipments. The method for growing single crystals of barium titanate and barium titanate solid solutions according to this invention can be also applicable to other material systems showing abnormal grain growth behavior.

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Asan, South Korea

Tae-Moo Hur