Non-ohmic Electrical Transport Properties Above the Critical Temperature in Optimally and Underdoped Superconducting YBa2Cu3O6+x

• Published in: Journal of superconductivity and novel magnetism 2012-07, Vol.25 (5), p.1361-1364
• Main Authors: Lang, W., Puica, I., Zechner, G., Kitzler, T., Bodea, M. A., Siraj, K., Pedarnig, J. D.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity; COPPER OXIDE; CURRENT DENSITY; DENSITY; DOPING; ELECTRICAL CONDUCTIVITY; Electrical resistivity; Exact sciences and technology; Halls; High-tc films; Magnetic Materials; Magnetism; Nonlinearity; Optimization; Original Paper; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Strongly Correlated Systems; Superconducting films and low-dimensional structures; SUPERCONDUCTIVITY; SUPERCONDUCTORS; THIN FILMS; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); YTTRIUM OXIDE
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-012-1660-8

The resistivity and the Hall effect as a function of current density and temperature in the normal state of very thin films of YBa 2 Cu 3 O 6+ x are measured with a fast pulsed-current technique. The in-plane longitudinal and transverse (Hall) conductivities are reduced in intense current densities up to several . In optimally-doped samples, this non-ohmic effect is limited to temperatures below 100 K. In a moderately underdoped sample, however, the non-linearity extends to the temperature range from T c =53 K to ∼150 K. The non-linear part of the Hall conductivity does not scale with a critical exponent, thus excluding classical amplitude fluctuations of the superconducting order parameter as possible origin.