Y Kunii, T Suzuki, A Kakishima, T Goto, S Nakajima, T Fukase
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS 388 257-258 2003年5月
Tl, Cu-NMR study has been performed on the high-T-c cuprate, TlBa2Y1-xCaxCu2O7 with wide range hole concentration from the antiferromagnetic (x = 0) to the slightly overdoped (x = 1.0). For superconducting samples (x = 0.6-1.0) the local spin susceptibility (K-S) at Cu-site stayed constant around room temperature, and starts slight a decrease from 160 K, which is higher than T-c. This T-dependence is what has been reported in other high-T-c cuprates in overdoped region. (T1T)(-1) at Tl-site for every superconducting sample, which obeys Curie-Weiss law at high temperature, showed a significant reduction from T-SG (> T-c), suggesting the existence of spin-gap even in slightly overdoped region. (C) 2003 Elsevier Science B.V. All rights reserved.