Effect of a change in the carrier concentration and disorder on the superconducting transition temperature of the La2−xSrxCu1−yNiyO4 system

✍ Scribed by K. Sreedhar; P.A. Metcalf; J.M. Honig

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 785 KB
• Volume: 227
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90369-7

✦ Synopsis

Electrical resistivity and magnetization measurements have been carried out on the La,\,Sr,Cu,\,,Ni,,O, system with 0.05 Ix< 0.25 and 0 I ~50.08. The superconducting transition temperature (T,) as well as the Sr composition range at which superconductivity occurs both show a progressive decrease with increasing Ni content or disorder (y). Above a critical Ni concentration or disorder (y,) a complete suppression of superconductivity is found in the entire range of Sr (hole) concentration. The p(T) and x(T) data indicate that weak disorder (y y,, however, the superconducting phase is completely suppressed; with increasing carrier concentration a crossover occurs from a strongly localized to a normal metallic phase, which exhibits weak localization effects at low temperatures. From these results an electronic phase diagram is derived which describes the effect of changes in the carrier concentration as well as the strength of disorder on the superconducting transition temperature.