Superconducting and magnetic characteristics in the multilayered high-Tc cuprates TlBa2Ca2Cu3O10−y with Tc>130 K probed by Cu and Tl NMR: High value for Tc

作     者：H. Kotegawa Y. Tokunaga K. Ishida G.-q. Zheng Y. Kitaoka A. Iyo Y. Tanaka H. Ihara 

作者机构：Department of Physical Science Graduate School of Engineering Science Osaka University Toyonaka Osaka 560-8531 Japan Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Corporation (JST) Kawaguchi Saitama 332-0012 Japan National Institute of Advanced Industrial Science and Technology (AIST) Umezono Tsukuba 305-8568 Japan 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2002年第65卷第18期

页      面：184504-184504页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

摘      要：We report 63Cu and 205Tl nuclear magnetic resonance (NMR) measurements on trilayered high-Tc compounds TlBa2Ca2Cu3O10−y (Tl-1223) that were synthesized at a high pressure and exhibits a high value of superconducting (SC) transition temperature Tc130 K. In the SC state, the nuclear spin-lattice relaxation rate 1/T1 reveals a T3 behavior below Tc, followed by a T1T=const behavior at very low temperatures. The results are accounted for by the d-wave pairing model where the presence of the residual density of the states Nres(EF) is incorporated at the Fermi level to be consistent with the experiments. The important finding is that the size [in Nres(EF)] is much smaller for the present compounds of Tl-1223 with Tc130 K than for the previous Tl-2223. Correspondingly, it is shown that an NMR intensity at a satellite peak in the Tl-NMR spectrum, which originates from a possible substitution of Tl for Ca, is much smaller for the former than for the latter. The synthesis technique at a high pressure is found to be a good way to remove such a crystal imperfection due to Tl/Ca intersubstitution. We have demonstrated from a microscopic point of view that as a result of decreasing the degree of disorder effect, the Tc in Tl-1223 has revealed a value higher than 130 K.