HIGH-TC SUPERCONDUCTIVITY IN THE BAXY1-XCUO3-Y SERIES

Experimental results showed high and sharp superconducting transitions both in ac susceptibility and resistance. Zero resistance above 90 K and resistive transition widths of about 3 K were found in a wide range of compositions 0,50≤x≤0.80. For x below 0.50, the midpoint temperature of resistive transitions (T c1/2 ) was monotonically increasing with x. All onset χ-transition temperatures by ac susceptibility measurements were close to those of R-transitions