Characteristic of local electron structure, O–T phase transition and superconductivity for oxygen-deficient YBa2Cu3O7−δ systems

✍ Scribed by Jincang Zhang; Yujian Cui; Dongmei Deng; Zhenping Chen; Xigui Li; Guosheng Cheng

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 118 KB
• Volume: 263
• Category: Article
• ISSN: 0375-9601
• DOI: 10.1016/s0375-9601(99)00760-4

✦ Synopsis

The oxygen deficient YBa Cu O d s 0.06 ; 0.68 has been studied by positron lifetime experiment at normal state 2 3 7 yd 300 K. It is found that there exists an abrupt change of positron lifetime parameter near Orthorhombic-Tetragonal phase transition. The local electron density n and vacancy concentration C are evaluated as a function of oxygen deficiency d. e v

The effect mechanism of local electronic structure on charge transfer and superconductivity is given in detail. The results show the existence of weak localization of electrons in tetragonal phase. The positron annihilation mechanism and its relation with superconductivity are also discussed.