Superconductivity at 155 K

• Published in: Physical review letters Vol. 58; no. 24; pp. 2579 - 2581
• Main Authors: OVSHINSKY, S. R, YOUNG, R. T, ALLRED, D. D, DEMAGGIO, G, VAN DER LEEDEN, G. A
• Format: Journal Article
• Language: English
• Published: Ridge, NY American Physical Society 15-06-1987
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Physics; Properties of type I and type II superconductors; Superconductivity; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); Temperature; Electrical conductivity; Transition metal Compounds; Experimental study; Non stoichiometric composition; Barium Copper Yttrium Fluorides oxides Mixed; Meissner effect; Inorganic compound; Magnetic moment; Magnetic susceptibility; Heterogeneous material; Flux pinning; Preparation; Chemical composition; Ceramic materials; High temperature superconductor; Superconducting transition; Low temperature
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.58.2579

Transition to a superconducting zero-resistance state at 155 K is observed for the first time in bulk material. A new five-element compound has been synthesized with nominal composition Y1Ba2Cu3F2Oy. Fluorine plays a critical role in achieving this effect. X-ray diffraction and electron microprobe analysis indicate that the samples are multiphasic. Evidence is presented that the samples contain superconducting phases with onset temperatures considerably above 155 K. Magnetic measurements suggest a flux-trapping effect below 260 K, and diamagnetic deviations from Curie-Weiss behavior in the range T of between 250 and 100 K, inclusively, indicate a Meissner effect in a small superconducting volume fraction. (Author)