Nonlinear electrodynamics in the granular superconductor YBa/sub 2/Cu/sub 3/O/sub 7/: Experiments and interpretation

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.11526· OSTI ID:6258245

Jeffries, C D; Lam, Q H; Kim, Y; Kim, C M; Zettl, A; Klein, M P

For bulk samples of superconducting YBa/sub 2/Cu/sub 3/O/sub 7/ powder and pellets subject to a dc magnetic field /ital H//sub 0/ and a parallel ac magnetic field /ital H//sub 1/ at frequency /ital f/approx.10/sup 3/ to 10/sup 5/ Hz, we report data on the generated harmonic power /ital P/(/ital nf/) up to harmonic /ital n/approx.40, finding: (1) If /ital H//sub 0/=0, only odd harmonics; (2) if /ital H//sub 0//ne/0, even harmonics are additionally generated; (3) for /ital H//sub 1/ sufficiently large (/approx gt/10 Oe) and /ital n/ large, then /ital P/(/ital nf/) vs /ital H//sub 0/ displays sharp and deep periodic dips, revealing a remarkably consistent and reproducible macroscopic flux quantization for the bulk sample. These data, as well as the relative intensities of the harmonic power, are found to be in semiquantitative agreement with detailed numerical predictions of a dynamical model of the material as a suitably averaged ensemble of prototype flux quantized loops with weak links. At lower values of /ital H//sub 1/ additional structure is observed, related to fluxon pinning and depinning.

• Research Organization: Physics Department, University of California, Berkeley, California 94720(US); Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720; Calvin Laboratory, Lawrence Berkeley Laboratory, Berkeley, California 94720
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6258245
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:16; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRODYNAMICS
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
FREQUENCY MIXING
GRANULAR MATERIALS
HARMONIC GENERATION
LOW TEMPERATURE
MAGNETIC FIELDS
MATERIALS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NONLINEAR PROBLEMS
OXIDES
OXYGEN COMPOUNDS
PELLETS
PHYSICAL PROPERTIES
POWDERS
SQUID DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES