Ishikawajima-Harima Jukogyo Kabushiki Kaisha

International Superconductivity Technology Center

Superconductivity Research Laboratory

Makoto Kambara

Shoji Tanaka

Yuh Shiohara

Minoru Tagami

Xin Yao

Hidetaka Satoh

Kouichi Miyake

There is provided a method for preparing a large and perfect oxide crystal useful for oxide superconductors and laser transmitting elements. In the present method for preparing a large oxide single crystalline material such as superconductive crystals of RE123, a crystal precursor material is supercooled prior to the solidification thereof in the course of crystal growth of the oxide by a supercooling solidification process, followed by subjecting said precursor material to continuous slow heating while keeping the supercooled condition to promote crystal growth, as shown in FIG. 7. Seed crystals may be added to the crystal precursor material prior to solidification, if necessary, as also shown in FIG. 7.

Method for preparing oxide single crystalline materials

The present invention is aimed to provide a means for manufacturing a RE123 system oxide superconductor showing good superconductivity characteristics under atmospheric ambiance. In a method of manufacturing a RE123 system oxide superconductor by melting, cooling and solidifying material including rare-earth elements and a Ba--Cu--O solvent for crystallization such as by the crystal pulling method, examining beforehand the relationship between the melted material composition and the equilibrium liquid-phase composition and the crystal composition of the RE123 system oxide superconductor formed therefrom in atmospheric ambiance, and based on the result of said examination, adjusting the average composition of the material or the composition of the solvent (for example, setting the average composition of the material to an area where the superconductivity phase and the liquid phase coexist in equilibrium, and at the same time adjust the 'Ba/Cu' ratio of the melted material to 3/5-1/1, or adjust the 'Ba/Cu' ratio of the solvent inside the crystal pulling crucible to 3/5-1/1), in order to control the amount of mutual substitution between RE and Ba (control the value of x in RE123 system superconductor RE.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-d to 0-0.05 and the like) for crystallization.

Method of manufacturing oxide superconductors

Growing community of inventors

Tokyo, Japan

Makoto Kambara