Characterization of Tl2Ba2CaCu2O8-Films and Single Crystals by an AC-Susceptibility Method

  • Ch. Neumann
  • Ch. Heinzel
  • P. Ziemann
  • W. Y. Lee

Abstract

A specially designed ac-susceptometer is described, which allows one to determine the anisotropy of the magnetic response of small (0.08×0.5×0.6mm) HTSC-crystals or thin films. The technique is illustrated by two examples: 1. Determination of the penetration length λ(0) for Tl2Ba2CaCu2O8 films with the external field parallel to the film surface. 2. Anisotropic behavior of the magnetic losses, as given by the imaginary part χ″ (T), in Tl2Ba2CaCu2O8 single crystals with fields perpendicular and parallel to the c-axis. Additional results on a tilted crystal (20° tilt of the c-axis relative to the external field) are discussed in terms of a possible flux line entanglement transition.

Keywords

Vortex Anisotropy Sapphire Thallium Grease 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    D.R. Nelson, Vortex Entanglement in High-T Superconductors, Phvs. Rev. Lett. 60, 1973 (1988).ADSCrossRefGoogle Scholar
  2. [2]
    D.R. Nelson and H.S. Seung, Theory of melted flux liquids, Phvs. Rev. B 39. 9153 (1989).ADSCrossRefGoogle Scholar
  3. [3]
    S.P. Obukhof and M. Rubinstein, Topological Glass Transition in Entangled Flux State. Phvs. Rev. Lett. 65. 1279 (1990).ADSCrossRefGoogle Scholar
  4. [4]
    E.H. Brandt, Thermal Fluctuation and Melting of the Vortex Lattice in Oxide Superconductors. Phvs. Rev. Lett. 63.1106 (1989).ADSCrossRefGoogle Scholar
  5. [5]
    M.V. Feigel’man, V.B. Geshkenbein and A.I. Larkin, Pinning and Creep in Layered Superconductors. Phvsica C 167, 177 (1990).Google Scholar
  6. [6]
    M.P.A. Fisher, Quantum Phase Transitions in Disordered Two-Dimensional Superconductors. Phys. Rev. Lett. 65, 923 (1990).ADSCrossRefGoogle Scholar
  7. [7]
    D. Feinberg and C. Villard, Intrinsic Pinning and Lock-in Transition of Flux Lines in Layered Type-II Superconductors, Phvs. Rev. Lett. 65, 919 (1990).ADSCrossRefGoogle Scholar
  8. [8]
    P.H. Kes, J. Aarts, V.M. Vinokur and C.J. van der Beek, Dissipation in Highly Anisotropic Superconductors. Phvs. Rev. Lett. 64, 1063 (1990).ADSCrossRefGoogle Scholar
  9. [9]
    G. Ziebold and D. Korn, Apparatus for the measurement of the initial susceptibility of quench-condensed spin glass films, J. Phys. E: Sci. Instrum. 12, 490 (1979).ADSCrossRefGoogle Scholar
  10. [10]
    Ch. Neumann, P. Ziemann, J. Geerk and H.C. Li, Characterization of YBaCuO Films by a.c.-Susceptibility Measurements. J. Less-Common Met. 151. 363 (1989).CrossRefGoogle Scholar
  11. [11]
    L. Lichti, K.C.B. Chan, D.W. Cooke and C. Boekema, Coupling strengths and flux pinning in oxide superconductors. Appl. Phvs. Lett. 54, 2361 (1989).Google Scholar
  12. [12]
    H.H. Otto, T. Zetterer and K.F. Renk, Preparation and structural investigation of normalconducting and high-T superconducting (Tl,Pb)Sr2(Ca,Tl)Cu2O7-y, Z. Phys. B: Condensed Matter 75. 433 (1989).ADSCrossRefGoogle Scholar
  13. [13]
    Ch. Heinzel, Ch. Neumann and P. Ziemann, Anisotropy of the Irreversible Magnetic Behaviour of YBaCuO and TlBaCaCuO Single Crystals — A Comparative a.c.-Susceptibility Study. Europhys. Lett. 13. 531 (1990).ADSCrossRefGoogle Scholar
  14. [14]
    M. Nikolo, Design of a high-field susceptometer and measurements of thallium based single crystals, this volume.Google Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • Ch. Neumann
    • 1
  • Ch. Heinzel
    • 1
  • P. Ziemann
    • 1
  • W. Y. Lee
    • 1
    • 2
  1. 1.Fakultät für PhysikUniversität KonstanzKonstanzGermany
  2. 2.IBM Almaden Research CenterSan JoseUSA

Personalised recommendations