Study of the Superconducting Proximity Effect of Cu-Nb systems with Magnetic Impurities and Application for the New Superconducting Wire.

1.本文研究了含Fe、Co、Ni、Mn等磁性杂质的Cu包Nb丝试样的迈斯纳效应。在10 mK-10 K的温度范围内，用交流阻抗法进行了测量。法由于近藤效应，在铜与这些磁性杂质观察到大的退配对效应。迈斯纳区域P在整个温度范围内与T^<-1/2>成正比。结果表明，自旋翻转散射的s-d交换相互作用的概率几乎不变的温度范围内。最近，Narikiyo和Fukuyama计算了P的温度依赖性，指出在近藤温度T_K以下，P随温度的降低而增加。我们的结果与计算结果不一致，含磁性杂质的铜包线正在进一步的应用研究中，以开发新的超导线材材料.对Cu和Nb薄多层膜进行了NMR研究。从Cu核自旋晶格弛豫时间T_1的测量中发现，超导能气是由邻近效应引起的。正如我们所期望的那样，超导电子和正常电子在Cu中共存。

1. The Meissner effect of Cu clad Nb wire samples with magnetic impurities such as Fe, Co, Ni and Mn has been studied. The measurements was done over the temperature range of 10mK-10K by means of the a.c. method. The large depairing effect due to the Kondo's effect was observed in Cu with these magnetic impurities. The Meissner region, P, was found to be proportional to T^<-1/2> over the temperature range. The result implies that the probability of the spin-flip scattering by the s-d exchange interaction is almost unchanged over the temperature range. Recently, Narikiyo and Fukuyama have calculated the temperature dependence of P. They indicate that P increases below Kondo's temperature T_K as decreasing temperature. Our results are not consistent with the calculation.The Cu clad wire with magnetic impurities is under further investigation for application, in order to develop new materials for the superconducting wires.2. The NMR study was carried out of the Cu and Nb thin multi-layers. From the measurements of the nuclear spin lattice relaxation time, T_1, of Cu nuclei, the superconducting energy gas was found to be induced by the proximity effect. Both superconducting and normal electrons were found to coexist in Cu as our expectation.