INVESTIGATION OF THE CRYSTAL-GROWTH OF CUO FROM THE CUO-BI2O3 SYSTEM

The relationship between properties and structure in high-temperature superconducting copper oxides has stimulated the investigation on the properties of single crystal CuO. The phase diagram of CuO-CuBi2O4 has been established by improved thermogravimetric analysis (ITGA), differential thermal analysis (DTA) and X-ray diffraction. The crystallization temperature of CuO was determined by ITGA and the dependence of crystallization temperature on cooling rates showed about 20-degrees-C supercooling in the crystal growth of CuO from the CuO-Bi2O3 system. Using the theory of crystal growth under stable state conditions, an initial kinetic analysis of seed crystal dissolution was also performed on the ITGA data. Using the phase diagram and the ITGA information, large crystals have been grown near the surface of the high-temperature solution or the bottom of the crucible by a combination of ITGA and the top-seeding method.