We have artificially varied the coupling between ultrathin YBa2Cu3O7 layers by interposing insulating planes of PrBa2Cu3O7 in multilayers and studied the consequences of decoupling 12-A YBa2Cu3O7 unit cells on the superconducting properties. We find that the Tc (midpoint) of a 12-A/12-A multilayer is 55 K, twice that of the corresponding alloy. Tc decreases linearly with further separation of the YBa2Cu3O7 unit cells, the transition width increases and shows evidence of 2D fluctuations, and the influence of a magnetic field parallel to the layers is markedly reduced.
ASJC Scopus subject areas
- Physics and Astronomy(all)