Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Substrate induced proximity effect in superconducting niobium nanofilms   Structural and superconducting properties of high quality Niobium nanofilms
with different thicknesses are investigated on silicon oxide and sapphire
substrates. The role played by the different substrates and the superconducting
properties of the Nb films are discussed based on the defectivity of the films
and on the presence of an interfacial oxide layer between the Nb film and the
substrate. The X-ray absorption spectroscopy is employed to uncover the
structure of the interfacial layer. We show that this interfacial layer leads
to a strong proximity effect, specially in films deposited on a SiO$_2$
substrate, altering the superconducting properties of the Nb films. Our results
establish that the critical temperature is determined by an interplay between
quantum-size effects, due to the reduction of the Nb film thicknesses, and
proximity effects.

29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol