Superconducting energy gaps in Bi2Sr2-xNdxCuO6+y (0≤x≤0.7) with Tc=6.5-20 K have been studied by the electron tunneling technique. The smallest gap value was found at ±2 meV for x=0 with Tc=6.5 K. The obtained gap values almost scale with x and thus Tc throughout the superconducting phase. The ratio 2Δpeak/kBTc=7.1 (2Δ/kBTc=4-5 with Δ from the BCS analysis) for the sample with Tc=6.5 K is still larger than the BCS ratio 3.5 of non-copper oxides (BaPb0.75Bi0.25O3 and Li1+xTi2-xO4) with Tc=11-12 K, indicating a substantial pairing nature difference between them.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering