Title :
Electron tunneling into 1-2-3 HTSC thin films
Author :
Geerk, J. ; Wang, R.L. ; Li, H.C. ; Linker, G. ; Meyer, O. ; Ratzel, F. ; Smithey, R. ; Keschtkar, H.
Author_Institution :
Inst. fuer Nukleare Festkorperphys., Karlsruhe, Germany
fDate :
3/1/1991 12:00:00 AM
Abstract :
Detailed tunneling measurements on thin-film planar tunnel junctions of the type RE1Ba2Cu3O7 /native oxide/Pb (RE=Y, Eu, or Gd) are reported. The films were sputter deposited and chemically etched prior to the growth of the native oxide. The structural content of the gaplike structure in the I-V characteristic was investigated by taking dI /dV and d3I/dV3 traces. By analysis of the temperature dependence and temperature smearing, strong arguments could be provided for the fact that all the structures between ±50 mV measured at low temperature are due to density of states effects. On junctions prepared on 1-2-3 films with Tc depressed either by partial oxygen depletion or by alloying, it is found that the gaplike structure was weakened, but did not shift on the energy scale
Keywords :
barium compounds; europium compounds; gadolinium compounds; high-temperature superconductors; superconducting junction devices; superconducting thin films; yttrium compounds; 1-2-3 HTSC thin films; I-V characteristic; d3I/dV3 curves; dI/dV curves; density of states effects; gaplike structure; high temperature superconductors; temperature dependence; temperature smearing; thin-film planar tunnel junctions; tunneling measurements; Alloying; Chemicals; Density measurement; Electrons; Sputter etching; Sputtering; Temperature dependence; Temperature measurement; Transistors; Tunneling;
Journal_Title :
Magnetics, IEEE Transactions on
