Tunneling Microscopy of Superconductors and Tunneling Barriers

Abstract

A cold stage was built for in-situ UPS measurements. Preliminary results show a fermi edge that disappears as the sample is warmed up in a vacuum. This surface degradation is reversible by annealing at 400C in pure oxygen. The films made by co-evaporation have improved. Films on bare silicon have zero resistance by 73K. The best films grow on SrTiO3 (110) with zero resistance by 84K and critical current densities greater than l million A/cm2 below 67K. A unique system of loadlocks has been implemented that allows us to transfer a film from the synthesis chamber to the low temperature STM for analysis. This has yielded, for the first time, good images of the YBCO surface. Spectroscopic measurements indicate thus far that most of the surface is normal, with a few spots showing superconducting behavior and a large superconducting gap.

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Document Details

Document Type
Technical Report
Publication Date
Aug 09, 1989
Accession Number
ADA212120

Entities

People

  • Alex De Lozanne

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Current Density
  • Evaporation
  • Films
  • High Temperature
  • Low Temperature
  • Materials
  • Microscopy
  • New Jersey
  • Oxidation
  • Quantum Tunneling
  • Resistance
  • Superconductivity
  • Superconductors
  • Thin Films
  • Tunneling
  • Universities

Fields of Study

  • Physics

Readers

  • Mathematics or Statistics
  • Thin Film Deposition Science.