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Title: Investigation of TiO{sub x} barriers for their use in hybrid Josephson and tunneling junctions based on pnictide thin films

We tested oxidized titanium layers as barriers for hybrid Josephson junctions with high I{sub c}R{sub n}-products and for the preparation of junctions for tunneling spectroscopy. For that we firstly prepared junctions with conventional superconductor electrodes, such as lead and niobium, respectively. By tuning the barrier thickness, we were able to change the junction's behavior from a Josephson junction to tunnel-like behavior applicable for quasi-particle spectroscopy. Subsequently, we transferred the technology to junctions using Co-doped BaFe{sub 2}As{sub 2} thin films prepared by pulsed laser deposition as base electrode and evaporated Pb as counter electrode. For barriers with a thickness of 1.5 nm, we observe clear Josephson effects with I{sub c}R{sub n}≈90 μV at 4.2 K. These junctions behave SNS'-like (SNS: superconductor-normal conductor-superconductor) and are dominated by Andreev reflection transport mechanism. For junctions with barrier thickness of 2.0 nm and higher, no Josephson but SIS'- (SIS: superconductor-insulator-superconductor) or SINS'-like (SINS: superconductor-normal conductor-insulator-superconductor) behavior with a tunnel-like conductance spectrum was observed.
Authors:
; ; ; ; ;  [1] ; ; ; ;  [2] ;  [3] ;  [4]
  1. Institute of Solid State Physics, Friedrich-Schiller-Universität Jena, Helmholtzweg 5, 07743 Jena (Germany)
  2. Institute for Metallic Materials, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany)
  3. Institute for Solid State Research, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany)
  4. Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01171 Dresden (Germany)
Publication Date:
OSTI Identifier:
22278014
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BARIUM COMPOUNDS; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; ENERGY BEAM DEPOSITION; IRON ARSENIDES; JOSEPHSON JUNCTIONS; LASER RADIATION; LAYERS; NIOBIUM; PULSED IRRADIATION; QUASI PARTICLES; SUPERCONDUCTORS; THIN FILMS; TITANIUM; TITANIUM OXIDES; TUNNEL EFFECT