Mechanism of the size dependence of the superconducting transition of nanostructured Nb
Mechanism of the size dependence of the superconducting transition of nanostructured Nb
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DOI：
10.1103/physrevlett.95.147003
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发表时间：
2005-09-30
影响因子：
8.6
通讯作者：
Ayyub, P
中科院分区：
文献类型：
--
作者：
Bose, S;Raychaudhuri, P;Ayyub, P
通过点接触光谱法直接测量纳米结构Nb膜的超导能隙表明，随着平均颗粒尺寸的减小，差距减小。从传输和磁性测量获得的超导Tc也随着尺寸和能隙的尺度而减小。因此，这种中间耦合II型超导体的超导性质的大小依赖性是由电子态密度的变化，而不是由声子软化。与安德森标准一致，对于小于8 nm的尺寸没有观察到T-c。
A direct measurement of the superconducting energy gap by point contact spectroscopy in nanostructured Nb films shows that the gap decreases with a reduction in the average particle size. The superconducting T-c, obtained from transport and magnetic measurements, also decreases with size and scales with the energy gap. The size dependence of the superconducting properties in this intermediate coupling type II superconductor is therefore governed by changes in the electronic density of states rather than by phonon softening. Consistent with the Anderson criterion, no T-c was observed for sizes below 8 nm.