Superconducting energy gaps in Bi2Sr2CuO6+y and Bi2Sr2−xNdxCuO6+y

✍ Scribed by Toshikazu Ekino; Tohru Den; Jun Akimitsu

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 655 KB
• Volume: 218
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90041-n

✦ Synopsis

Superconducting energy gaps in Bi2Sr2_xNdxCuO6+y (0 ~< x~< 0.7 ) with T¢ = 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 T¢ = 6.5 K. The obtained gap values almost scale with x and thus T~ throughout the superconducting phase. The ratio 2dr~k/kBT¢= 7.1 (2,J/keT¢= 4-5 with zl from the BCS analysis) for the sample with T¢ = 6.5 K is still larger than the BCS ratio 3.5 of non-copper oxides (BaPbo.75Bio.2503 and Li~ +xTi2_xO4) with T¢ = 11-12 K, indicating a substantial pairing nature difference between them.