205Tl NMR in oxygen depleted cuprate superconductors Tl2Ba2CaCu2O8−δ

✍ Scribed by N. Winzek; Hj. Mattausch; S.-G. Eriksson; C. Ström; R.K. Kremer; A. Simon; M. Mehring

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 714 KB
• Volume: 205
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90167-o

✦ Synopsis

We report on the NMR Knight shift of 2°5T1 in Tl2Ba2CaCuzO8_~ for different ~. Due to the variation of the oxygen content, T c ranges from 85 K up to 105 K. The 2°~T1 spectra consist of two lines, where the main line is due to Tl( l ) in the TiP-layer whereas the defect line corresponds to Tl (2) replacing Ca. The shift of the TI (2) line is observed to be strongly dependent on the oxygen content and is therefore a measure of the hole concentration. It shows a negative Knight shift, and behaves very much like 89y in YBa2Cu307_ 6. In contrast the Tl ( 1 ) line shows strong antiferromagnetic correlations with indication of a pseudo spin gap which exists already above the superconducting transition temperature T¢.