The Hall effect in untwinned single-crystal superconducting YBa[sub 2]Cu[sub 3]O[sub 7[minus]y]

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5578800

Rice, J P

The author has measured the Hall effect in untwinned single-crystal YBa[sub 2]Cu[sub 3]O[sub 7[minus]y], a high-[Tc] superconductor. The crystals were grown using a technique that he invented, in which untwinned domains are produced naturally without applying stress to the sample. The Hall effect measurements were directed at understanding fluctuation phenomena just above [Tc], where small regions of a sample experience short-lived thermodynamic fluctuations into the superconducting state. Effects from these fluctuations appear in the temperature dependences of the Hall coefficient and conductivity as substantial deviations from the 1/T normal-state behavior. Because the original Fukuyama, Ebisawa, and Tsuzuki theory of the fluctuation-induced Hall effect is for an isotropic superconductor and YBa[sub 2]Cu[sub 3]O[sub 7[minus]y] is a layered material, the author compared the data to an extended version. He calculated terms that were lacking and corrected mistakes in the literature to arrive at a complete and consistent theory for the effect of fluctuations on the Hall effect in a layered superconductor. From the fits of this theory to the data it was possible to obtain fundamental information, such as the size of the superconducting coherence length and the nature of the coupling of the superconducting planes within the crystal structure of YBa[sub 2]Cu[sub 3]O[sub 7[minus]y]. Below [Tc], information was obtained about vortex motion from the Hall effect and magnetoresistance. For example, it was found that the Hall resistivity changes sign over a certain range of magnetic field and temperature below [Tc], even in untwinned crystals. Thus this anomalous behavior, originally discovered in twinned samples, is not due to effects of twin planes.

• Research Organization: Illinois Univ., Urbana, IL (United States)
• OSTI ID: 5578800
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
665411 -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENCE LENGTH
COPPER COMPOUNDS
COPPER OXIDES
COUPLING
CRYSTAL STRUCTURE
CRYSTALS
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HALL EFFECT
HIGH-TC SUPERCONDUCTORS
INTERMETALLIC COMPOUNDS
LENGTH
MAGNETIC FIELDS
MAGNETORESISTANCE
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES