Abstract: 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.

Abstract: A piezoelectric single crystal and piezoelectric and dielectric application parts using the same are provided, which have all of high dielectric constant K3T, high piezoelectric constants (d33 and k33), high phase transition temperatures (Tc and TRT), high coercive electric field Ec and improved mechanical properties and thus can be used in high temperature ranges and high voltage conditions. Furthermore, the piezoelectric single crystals are produced by the solid-state single crystal growth adequate for mass production of single crystals and the single crystal composition is developed not to contain expensive raw materials so that the piezoelectric single crystals can be easily commercialized. With the piezoelectric single crystals and piezoelectric single crystal application parts, the piezoelectric and dielectric application parts using the piezoelectric single crystals of excellent properties can be produced and used in the wide temperature range.

Abstract: 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.

Abstract: A piezoelectric single crystal and piezoelectric and dielectric application parts using the same are provided, which have all of high dielectric constant K3T, high piezoelectric constants (d33 and k33), high phase transition temperatures (Tc and TRT), high coercive electric field Ec and improved mechanical properties and thus can be used in high temperature ranges and high voltage conditions. Furthermore, the piezoelectric single crystals are produced by the solid-state single crystal growth adequate for mass production of single crystals and the single crystal composition is developed not to contain expensive raw materials so that the piezoelectric single crystals can be easily commercialized. With the piezoelectric single crystals and piezoelectric single crystal application parts, the piezoelectric and dielectric application parts using the piezoelectric single crystals of excellent properties can be produced and used in the wide temperature range.

Abstract: 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.

Abstract: The invention relates to a method for growing single crystals in polycrystalline bodies in which abnormal grain growth occurs. The method is characterized by controlling the average size of matrix grains of polycrystalline bodies in which abnormal grain growth occurs, whereby reducing the number density (number of abnormal grains/unit volume) of abnormal grains to generate only a extremely limited number of abnormal grains or inhibit the generation of abnormal grains within the extent of guaranteeing the driving force of abnormal grain growth. Therefore, the invention grows continuously only the extremely limited number of abnormal grains or only the seed single crystal into the polycrystalline body to obtain a large single crystal having a size larger than 50 mm.

Abstract: 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.

Abstract: The invention relates to a method for growing single crystals of barium titanate [BaTiO3] and barium titanate solid solutions [(BaxM1−x)(TiyN1−y)O3]. 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.

Abstract: The invention relates to a method for growing single crystals of barium titanate [BaTiO3] and barium titanate solid solutions [(BaxM1-x)(TiyN1-y)O3]. 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.

Abstract: The invention relates to a method for growing single crystals of barium titanate [BaTiO3] and barium titanate solid solutions [(BaxM1-x)(TiyN1-y)O3]. 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.