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Size dependence of the Tc and the superconducting energy gap in nanocrystalline thin films of Nb

Sangita Bose·Pratap Raychaudhuri·Rajarshi Banerjee·Parinda Vasa·Pushan Ayyub
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Abstract

In nanocrystalline Nb films, the superconducting Tc decreases with a reduction in the average particle size below 20nm. We correlate the decrease in Tc with a reduction in the superconducting energy gap measured by point contact spectroscopy. Consistent with the Anderson criterion, no superconducting transition was observed for sizes below 8 nm. We show that the size-dependence of the superconducting properties in this intermediate coupling Type II superconductor is governed by changes in the electronic density of states rather than by phonon softening.

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Sangita Bose, Pratap Raychaudhuri, Rajarshi Banerjee, Parinda Vasa, Pushan Ayyub. 2004-09-01. Size dependence of the Tc and the superconducting energy gap in nanocrystalline thin films of Nb. https://doi.org/10.1103/physrevlett.95.147003

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