CHARACTERIZATION AND SUPERCONDUCTIVITY OF YBA2CU4O8 AND Y2BA4CU7O14+X AND THEIR INTERGROWTHS

Pure single phase Y2Ba4Cu7O14+x (“247”) and two phase compositions containing either “123” or “124” inclusions were prepared under 85 bar oxygen pressure at 1000°C. The samples were characterized by X-ray diffraction, microprobe analysis and microstructural examination. The measurements of the a.c. susceptibility, the field cooling magnetization and the resistivity indicate that Tc of “247” is actually higher than that of “124” but suggest a more pronounced influence of oxygen defects in “247” under the present conditions of synthesis. © 1990, Elsevier Science Publishers B.V. (North-Holland). All rights reserved.