Yttrium barium copper oxide

![Like all superconductors, YBCO displays the Meissner effect. Below its critical temperature, YBCO becomes perfectly diamagnetic and excludes sufficiently weak magnetic fields from passing through it.[4]](/uploads/202501/05/-Flyingsuperconductor.ogg0645.jpg)
Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds, famous for displaying "high-temperature superconductivity". It includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen (77 K) at about 90 K. Many YBCO compounds have the general formula YBa2Cu3O7-x (also known as Y123), although materials with other Y:Ba:Cu ratios exist, such as YBa2Cu4Oy (Y124) or Y2Ba4Cu7Oy (Y247).