https://doi.org/10.1007/s100510050429
Penetration depth measurement in high quality YBa2Cu3O7-x thin films
1
School of Physics and Astronomy, Raymond and Beverly
Sackler Faculty of Exact Science, Tel Aviv University, Ramat Aviv 69978, Israel
2
Department of Physical Electronics, Faculty of Engineering,
Tel Aviv University, Ramat Aviv 69978, Israel
3
UMR CNRS/Thomson-CSF,91404 Orsay, France
Corresponding author: a farber@post.tau.ac.il
Received:
22
July
1997
Revised:
11
March
1998
Accepted:
23
June
1998
Published online: 15 September 1998
The parallel plate resonator method has been used for measuring high quality YBa2Cu3O7-x (YBCO) thin films, which have low temperature residual losses comparable to those previously obtained in single crystals. The surface resistance and the real part of the conductivity show a non-monotonic behaviour with a broad peak around 45 K. The penetration depth and the real part of the conductivity vary linearly at low temperatures. The lowest penetration depth linear fitting has a slope value of 2.2 Å/K to 2.5 Å/K up to 20 K which is lower than previous measurements on YBCO single crystals. An interpretation of this smaller slope in terms of the generally accepted d-wave order parameter symmetry presents difficulties.
PACS: 74.25.Nf – Response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.) / 74.72.Bk – Y-based cuprates / 74.76.Bz – High-Tc films
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998