摘要
Internal friction (IF) measurement in the kHz frequency region has been performed for underdoped YBa2Cu3O7-δ. A rapid decrease of internal friction with decreasing temperature is observed at a temperature Τg (> Τc), which is considered as the opening of a pseudogap. Based on the feature of pseudogap described by V. J. Emery and BCS theory, a power law decrease of internal friction with temperature at Τg is derived and the index is estimated, which is consistent with the experiments. The decrease of the spin-lattice relaxation rate 1/Τ1 for NMR near 150 K in the underdoped YBCO, similar to that of internal friction, can be explained in the same way. Furthermore, in view of the different phase coherence effect on IF and 1/Τ1, it can be predicted that another decrease for internal friction will occur near Τc but not for 1/Τ1. The conclusion is confirmed by the experiments. In addition, the reported anomaly of resistivity near Τ*(∼ 160 K) for the underdoped YBCO is discussed too.
源语言 | 英语 |
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页(从-至) | 104-109 |
页数 | 6 |
期刊 | EPL |
卷 | 47 |
期 | 1 |
DOI | |
出版状态 | 已出版 - 1 7月 1999 |
已对外发布 | 是 |