Transport and magnetic properties of YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]]Br[sub [ital y]] single crystals

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.1148· OSTI ID:6393880

Nguyen, P P; Wang, Z; Rao, A M ^[1]; Dresselhaus, M S ^[2]; Moodera, J S; Dresselhaus, G ^[3]; Radousky, H B; Glass, R S ^[4]; Liu, J Z ^[5]

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1. Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. Department of Physics and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
3. Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
4. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
5. Department of Physics, University of California enDavis, Davis, California 95616 (United States)

Deoxygenated nonsuperconducting YBa[sub 2]Cu[sub 3]O[sub 6.2] (YBCO) single crystals have been doped with Br. The resulting crystals become superconducting with [ital T][sub [ital c]][similar to]92 K, [Delta][ital T][sub [ital c]][similar to]1.0 K as determined by four-point-probe resistivity measurements. The resistivity in our best sample decreases linearly with temperature. The large ratio in the resistivity at 300 K of the brominated to the pristine YBCO single crystals ([similar to]35:1) suggests that bromination greatly increases the scattering rate. The upper critical field [ital H][sub [ital c]2]([ital T]) parallel and perpendicular to the [ital ab] plane is determined resistively. [ital H][sub [ital c]2](0) and the corresponding coherence lengths [xi][sub [ital a][ital b]](0) and [xi][sub [ital c]](0) are estimated. A comparison with the fully oxygenated YBCO single crystals shows that [xi][sub [ital a][ital b]](0) remains approximately the same, whereas [xi][sub [ital c]](0) decreases by a factor of [similar to]3, suggesting that Br never enters the CuO[sub 2] planes. The pinning energy for vortex motion in the [ital ab] plane decreases after bromination and this decrease can be attributed to the increased anisotropy. For vortex motion along the [ital c] axis, however, the pinning energy decreases or increases depending on temperature and field. Compared with the fully oxygenated YBCO single crystals, the critical current density is suppressed by bromination and is strongly dependent on the applied magnetic field. The reduced lower critical field [ital H][sub [ital c]1] in the brominated YBCO single crystals indicates a reduction in the carrier density (by a factor of between 2 and 3), which is consistent with the observed reduction in the plasma frequency.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6393880
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:2; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
360207 -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BROMINE COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRITICAL FIELD
CRYSTALS
CUPRATES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HALOGEN COMPOUNDS
HIGH-TC SUPERCONDUCTORS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES