Planar tunneling junctions on Bi4Sr3Ca3Cu4O16+y (4334) which clearly exhibit the gap of the top electrode (In or Pb) have been prepared. Junction resistances range from 1Ω to 6kΩ over a 1 - 2mm2 area, the lower resistances being obtained only after plasma oxidation of the surface. We observe a linear conductance at varying biases above the gap region. No evidence of a gap in the 4334 material and no Josephson current has been observed even in the lowest resistance junctions. A short summary of the Bellcore work on the Cu-doped YBa2Cu3O7-y and La1.85Sr.15CuO4-y is also given.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering