51,661 research outputs found
Niobium-based superconducting nano-devices fabrication using all-metal suspended masks
We report a novel method for the fabrication of superconducting nanodevices
based on niobium. The well-known difficulties of lithographic patterning of
high-quality niobium are overcome by replacing the usual organic resist mask by
a metallic one. The quality of the fabrication procedure is demonstrated by the
realization and characterization of long and narrow superconducting lines and
niobium-gold-niobium proximity SQUIDs
Characterisation of Cryogenic Material Properties of 3D-Printed Superconducting Niobium using a 3D Lumped Element Microwave Cavity
We present an experimental characterisation of the electrical properties of
3D-printed Niobium. The study was performed by inserting a 3D-printed Nb post
inside an Aluminium cylindrical cavity, forming a 3D lumped element re-entrant
microwave cavity resonator. The resonator was cooled to temperatures below the
critical temperature of Niobium (9.25K) and then Aluminium (1.2K), while
measuring the quality factors of the electromagnetic resonances. This was then
compared with finite element analysis of the cavity and a measurement of the
same cavity with an Aluminium post of similar dimensions and frequency, to
extract the surface resistance of the Niobium post. The 3D-printed Niobium
exhibited a transition to the superconducting state at a similar temperature to
the regular Niobium, as well as a surface resistance of
. This value was comparable to many samples of traditionally machined
Niobium previously studied without specialised surface treatment. Furthermore,
this study demonstrates a simple new method for characterizing the material
properties of a relatively small and geometrically simple sample of
superconductor, which could be easily applied to other materials, particularly
3D-printed materials. Further research and development in additive
manufacturing may see the application of 3D-printed Niobium in not only
superconducting cavity designs, but in the innovative technology of the future.Comment: 5 pages, 4 figure
One hundred angstrom niobium wire
Composite of fine niobium wires in copper is used to study the size and proximity effects of a superconductor in a normal matrix. The niobium rod was drawn to a 100 angstrom diameter wire on a copper tubing
Single electron transistors with high quality superconducting niobium islands
Deep submicron Al-AlOx-Nb tunnel junctions and single electron transistors
with niobium islands were fabricated by electron beam gun shadow evaporation.
Using stencil masks consisting of the thermostable polymer polyethersulfone
(PES) and germanium, high quality niobium patterns with good superconducting
properties and a gap energy of up to 2Delta = 2.5 meV for the niobium were
achieved. The I(U) characteristics of the transistors show special features due
to tunneling of single Cooper pairs and significant gate modulation in both the
superconducting and the normal state.Comment: 4 pages, 4 figure
Ab-initio calculations for structural properties of Zr-Nb alloys
Ab-initio calculations for the structural properties of Zr-Nb alloys at
different values of the niobium concentration are done at zero temperature.
Different cases for Zr-Nb alloys with unit cells having BCC and HCP structures
are considered. Optimal values of the lattice constants are obtained. Critical
value for the niobium concentration corresponding to the structural
transformation HCP \rightarrow BCC at zero temperature is determined.
Electronic densities of states for two different structures with niobium
concentrations 12.5% and 25% having HCP and BCC structures, accordingly, are
studied.Comment: 8 pages, 4 figure
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