Dynamic conductivity near T{sub c} of YBa{sub >2}Cu{sub 3}O{sub 7} films: Vortex-glass-like criticality in the absence of externally induced vortices

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.6077· OSTI ID:467398

Nakielski, G; Goerlitz, D; Stodte, C; Welters, M ^[1]; Kraemer, A ^[2]; Koetzler, J ^[1]

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1. Institut fuer Angewandte Physik, Jungiusstrasse 11, D-20355 Hamburg (Germany)
2. TU Hamburg-Harburg, AB Halbleitertechnologie, Eissendorfer Strasse 42, D-21073 Hamburg (Germany)

Using a contactless method, we investigated the electrical ac conductivity {sigma}{sup {prime}}+i{sigma}{sup {double_prime}} in the CuO{sub 2} planes of thin Y-Ba-Cu-O films deposited on (001)-SrTiO{sub 3} and -MgO substrates at zero magnetic field. The temperature variation of the phase angles, {var_phi}(T;{omega})=arctan({sigma}{sup {double_prime}}/{sigma}{sup {prime}}), measured between 30 Hz and 2 GHz, allows a precise definition of the superconducting transition T{sub c}. Remarkably, the frequency-independent value {var_phi}(T{sub c})=74{degree}, obtained for both films, agrees with those observed previously for high vortex densities (0.1{endash}19 T), where this fact was associated with the universality near the so-called vortex-glass transition line. Since the shape of the present scaling function for {sigma}({omega}) also proves to be identical with that found in a high field, we argue that the same fluctuations destroy superconductivity in zero field and in the presence of a dense vortex lattice. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 467398
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 55; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
COPPER OXIDES
ELECTRIC CONDUCTIVITY
FLUCTUATIONS
FREQUENCY DEPENDENCE
HIGH-TC SUPERCONDUCTORS
MAGNETIC FLUX
MIXED STATE
SCALING LAWS
SUPERCONDUCTING FILMS
TEMPERATURE DEPENDENCE
THIN FILMS
YTTRIUM OXIDES