High temperature superconductor. Molecular model of part of the high temperature superconductor, YBCO-6. Superconductors transmit electrical current without any electrical resistance and hence with no energy loss. YBCO stands for the elements yttrium (Y), barium (B), copper (C) and oxygen (O) which form this substance. Atoms are colour-coded: oxygen (red), barium (yellow), yttrium (purple) and copper (blue). Copper atoms lie at the centre of copper oxide pyramids (blue). Superconductors which work at a relatively warm 30 Kelvin (-243 degrees celsius) were first created in 1986. High temperature superconductors such as this one can work at temperatures over 125 Kelvin.