Anisotropy of optical and transport properties in the a-b plane of the high temperature superconductor YBa2Cu4O8


Por: Schoenes J., Karpinski J., Kaldis E., Keller J., de la Mora P.

Publicada: 1 ene 1990
Resumen:
The anisotropy within the a-b plane of YBa2Cu4O8 has been studied on single crystal platelets by optical and electron transport measurements. The optical investigations include polarized reflectivity measurements at room temperature for photon energies between 0.5 and 4 eV and a direct measurement of the ratio of the reflectivity coefficients rb ra. The anisotropy of the electrical resistivity has been determined from AC van der Pauw measurements using the Montgomery formalism for anisotropic materials. The optical reflectivity spectra are dominated by Drude-like free electron contributions with plasmon energies of 2.8 eV and 1.67 eV for the electrical field vector along the b- and a-axis, respectively. The electrical resistivity displays an anisotropy of a factor of about 3. The superconducting transition temperature (midpoint of the resistivity drop) is 76 K. Contrary to YBa2Cu3O7, clear deviations from linear temperature dependences of the resistivity are observed in the normal state of YBa2Cu4O8. An extrapolation of the linear (normal) part gives zero resistance at 36 ± 2 K and not 0 K. The observed anisotropies are compared with results of a tight binding calculation. © 1990.

Filiaciones:
Schoenes J.:
 Laboratorium für Festkörperphysik, ETH Zürich, CH-8093 Zürich, Switzerland

Karpinski J.:
 Laboratorium für Festkörperphysik, ETH Zürich, CH-8093 Zürich, Switzerland

Kaldis E.:
 Laboratorium für Festkörperphysik, ETH Zürich, CH-8093 Zürich, Switzerland

Keller J.:
 Departamento de Fisica y Química Teórica, Facultad de Química, UNAM, 04510 México, DF, Mexico

de la Mora P.:
 Departamento de Fisica, Facultad de Ciencias, UNAM, 04510 Mexico, DF, Mexico
ISSN: 09214534
Editorial
Elsevier, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, Países Bajos
Tipo de documento: Article
Volumen: 166 Número: 1-2
Páginas: 145-150
WOS Id: A1990CW79100024