CRYSTAL GROWTH OF MULTI-LAYERED Ba2Ca4Cu5O10(O,F)2 (F-0245) SUPERCONDUCTOR UNDER HIGH PRESSURE

Single crystals of multi-layered Ba2Ca4Cu5O10(O,F)2 superconductor(F-0245) have been grown under a high pressure of 4.5 GPa. Single crystals with in-plane length of 500μm were typically obtained and flat shiny areas with more than 1mm2 were also observed on the surface of fractured samples. Tc values for these samples were determined by electrical resistivity measurements. These values were found to change from 70 K to 85 K by change of oxygen and fluorine contents in the starting mixture. The temperature dependence of resistivity showed characteristic of under-doped cuprate superconductors.