Yttrium barium copper oxide, or YBCO, chemical formula YBa₂Cu₃O_7-δ, is a high-temperature superconductor with a superconducting temperature of 94K. Its discovery by C.W. Chu in 1987 launched the era of high-temperature superconductors. It was the first superconductor to break the liquid nitrogen barrier, i.e. the first to be superconducting at a temperature high enough to permit the use of liquid nitrogen as a coolant. Because liquid nitrogen, at 77K, is significantly less expensive than liquid helium, YBCO made a large number of commercial applications feasible for the first time.

Yttrium barium copper oxide is used commercially in the fabrication of superconducting tapes and microwave filters.

Yttrium barium copper oxide is often referred to as 'YBCO' or '123'. It is classified as an anomalous superconductor.

External links

• http://www.ch.ic.ac.uk/otway/YBCO.html