| HETEROSTRUCTURES BASED ON HIGH-TEMPERATURE
SUPERCONDUCTING THIN FILMS |
| P. Prieto, W. Lopera, E. Baca, L. F. Castro, M.
E. Gómez |
For many possible electronic
applications as well as fundamental studies it is essential to fabricate
epitaxial layered structures of insulators, semiconductors or normal
metals together with high-temperature superconductors (HTS). However
HTS materials have complex lattice structures and this makes it
difficult to grow multilayers with sharp interfaces preserving epitaxiallity
through the whole structure. In this work we describe transport
measurements and microstructural analysis of YBa2Cu3O7-d / PrBa2Cu3O7-d
/ YBa2Cu3O7-d (YBCO / PBCO / YBCO) and Bi2Sr2CaCu2O8+d / Bi2Sr2YCu2O8+d
/ Bi2Sr2CaCu2O8+d (BSCCO / BSYCO / BSCCO) heterostructures deposited
on (001) SrTiO3 substrates by using an in situ DC sputtering technique
at high oxygen pressures. Conductance measurements on this type
of multilayers showed a clear quasiparticle tunneling indicating
a gap structure around 25 mV in the case of YBCO compounds, 30 -
35 mV and a zero bias anomaly in the case of BSCCO materials. We
will discuss also the Josephson behavior of heterostructures based
on BSCCO compounds. |
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