This was the starting point of an apparently exponential growth of Tc values. This was above the boiling point of liquid nitrogen and represented the promise of a new, more accessible technology of superconducting devices. The structure of the 123 superconductor is shown below. O 2- ions. Unit cells are outlined in yellow.
Blue pyramids represent the active copper ions coordinated by five oxide ions.
Tc's have been achieved. O 2- ions. Unit cells are outlined in yellow. Blue pyramids represent the active copper ions coordinated by five O 2 ions. The 130K record was reached in 1993 and since then things seem to have slowed down in this respect.