Al NMR probe of local moments induced by an Al impurity in high-Tc cuprate La 1.85Sr0.15CuO4.
Al NMR probe of local moments induced by an Al impurity in high-Tc cuprate La 1.85Sr0.15CuO4.
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高 Tc 铜酸盐 La 1.85Sr0.15CuO4 中 Al 杂质引起的局部矩的 Al NMR 探针。
DOI：
10.1103/physrevlett.76.531
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发表时间：
1996
影响因子：
8.6
通讯作者：
Yamada
中科院分区：
文献类型：
--
作者：
Ishida;Kitaoka;Yamazoe;Asayama;Yamada
在3% Al掺杂La 1.85 Sr 0.15 cuo4 （LSCO）中27 Al和63 Cu的核磁共振测量表明，Knight位移27 K (T)和核自旋-晶格弛豫速率27 （1/ t1）的T依赖性主要由Al杂质在邻近Cu位点诱导的局部矩决定。这些实验证明了诱导矩的自旋涨落主要是由于与导电空穴的局部自旋交换耦合。这种新颖的27 （1/ t1）的T依赖性导致了jsd = 0.055 eV的可靠估计，并且基于磁对破断方案提取的T - c还原率Δ T - c= 0.62 K/Al%，比实验值Δ T - c= 23 K/Al%小了一个多数量级。
27 Al and 63 Cu NMR measurements in 3% Al-doped La 1.85 Sr 0.15 CuO 4 (LSCO) have revealed that the T dependences of the Knight shift, 27 K (T), and the nuclear-spin-lattice relaxation rate, 27 (1/T 1), are dominated by local moments induced at neighboring Cu sites by the Al impurity. These experiments prove that spin fluctuation of induced moments is mainly due to the local spin-exchange coupling, J sd, with conducting holes. This novel T dependence of 27 (1/T 1) has led to a reliable estimation of J sd= 0.055 eV, and the extraction of the T c reduction rate, Δ T c= 0.62 K/Al% based on the magnetic pair-breaking scheme, which is by more than 1 order of magnitude smaller than the experimental value of Δ T c= 23 K/Al%.