The interlayer coupling of superconducting NbN thin films through metallic Ag and insulating CNx thin films has been investigated from resistivity measurements of [NbN(170 A ̊)/X(t A ̊)]10 (X Ag, CNx) multilayered films. When Ag layer thicknesses are thicker than 150 Åm NbN layers are decoupled and the transition temperatures are nearly equal 8.2 K. The transition transition temperature increases with decreasing Ag layer thickness, obeying Werthamer's theory for the proximity effect. On the other hand, with the increase of CNx layer thickness, the transition temperature is lowered steeply and almost linearly, indicating a coupling mechanism other than the proximity effect.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering