Break-junction tunneling measurements of the high-Tc superconductor Y1Ba2Cu3O9-

Abstract

Current-voltage tunneling characteristics in a high-critical-temperature superconducting material containing predominately Y1Ba2Cu3O9- have been measured using the break-junction technique. Sharp gap structure was observed, with the largest superconductive energy gap measured to be =19.51 meV, assuming a superconductor-insulator-superconductor junction. This energy gap corresponds to 2/kBTc=4.8 at T=4 K, for a critical temperature of 93 K (midpoint of the resistive transition). © 1987 The American Physical Society.