ASU Electronic Theses and Dissertations
- 2 English
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The study of high energy particle irradiation effect on Josephson junction tri-layers is relevant to applications in space and radioactive environments. It also allows us to investigate the influence of defects and interfacial intermixing on the junction electrical characteristics. In this work, we studied the influence of 2MeV Helium ion irradiation with doses up to 5.2×1016 ions/cm2 on the tunneling behavior of Nb/Al/AlOx/Nb Josephson junctions. Structural and analytical TEM characterization, combined with SRIM modeling, indicates that over 4nm of intermixing occurred at the interfaces. EDX analysis after irradiation, suggests that the Al and O compositions from the barrier are collectively …
- Zhang, Tiantian, Newman, Nathan, Rowell, John M, et al.
- Created Date
A series of Molybdenum-Copper bilayers were studied for use in 120mK superconducting transition edge sensors for spectrometer applications. The Transition temperature (T<sub>C</sub>) was tuned to the desired temperature using the proximity effect, by adjusting the thickness of a normal copper layer in direct contact with the superconducting molybdenum layer in a proximitized bilayer structure. The bilayers have a fixed normal metal thickness d<sub>Cu</sub>=1250 Å, on top of a variable superconductor thickness 650 Å ≤ d<sub>Mo</sub> ≤ 1000 Å. Material characterization techniques including X-ray Diffraction (XRD), Rutherford Backscattering Spectroscopy (RBS), Atomic Force Microscopy (AFM), and 4-point electrical characterization are used to …
- Kopas, Cameron J, Newman, Nathan, Singh, Rakesh, et al.
- Created Date