Superconductivity in Ni substituted Bi2Ca1Sr2Cu2−xNixOy

✍ Scribed by Pramada Kulkarni; S.K. Kulkarni; A.S. Nigavekar; S.K. Agarwal; V.P.S. Awana; A.V. Narlikar

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 392 KB
• Volume: 166
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(90)90055-j

✦ Synopsis

The effect of partial substitution of Ni in place of Cu in Bi,Ca,Sr~NiFuz_,O,, has been systematically investigated for 0~~~0.2. The XRD of the samples confirms them to be of single phase. The superconducting critical temperature T, monotonically decreases with Ni concentration; the rate of T, decrease is around 2.5 K/% of the nominal substitution. All the samples have been subjected to XPS studies. The results show that Ni is incorporated in the lattice in the divalent state with Ni-0 bonds substituting for the Cu-0 bonds while keeping Bi-0, Sr-0 and Ca-0 bonds intact. Change in the Ni content does not seem to affect the valence state of Cu. The question of r, decrease with Ni substitution is examined.