Superconductivity at 90 K in the Tl-Ba-Cu-O system

Z. Z. Sheng; A. M. Hermann; A. El Ali; C. Almasan; J. Estrada; T. Datta; R. J. Matson

doi:10.1103/PhysRevLett.60.937

Superconductivity at 90 K in the Tl-Ba-Cu-O system

Z. Z. Sheng, A. M. Hermann, A. El Ali, C. Almasan, J. Estrada, T. Datta, and R. J. Matson

Phys. Rev. Lett. 60, 937 – Published 7 March 1988

Abstract

Stable and reproducible superconductivity has been unambiguously observed in a new Tl-Ba-Cu-O system containing no group-IIIB elements. Resistance in these rare-earth–free oxides starts to drop sharply above 90 K and reaches zero at 81 K. Meissner flux expulsion and diamagnetic shielding show bulk superconductivity. Further substitutions of elements for this system may lead to even higher-temperature superconductors.