In previous work, a magnetically modulated microwave absorption (MMMA) technique to measure the Ginzburg-Landau parameter κ = (λ/ζ) in high-Tc superconductors (bulk samples of YBCO) was described. In this work, how this technique can be applied to the measurement of the London penetration depth λis described. Data are reported for the temperature variation of λ in a well-characterized c-axis-oriented polycrystalline thin film of YBa₂Cu₃O₇₋ₓ, prepared by a pulsed laser deposition technique. For low temperatures, λ(O) ≃3640 Å with the microwave electric field oriented parallel to the c axis. The temperature dependence of λ(0)/λ(T) can be well described by the two-fluid model. The data are also reasonably fit by a BCS model, however the MMMA technique (in the work here reported) does not have the resolution at low temperatures to obtain strong quantitative evidence for an energy gap Δ (even if it exists).


Originally published in Journal of Applied Physics 69, 4891 (1991). DOI:10.1063/1.348215 (http://dx.doi.org/10.1063/1.348215).


magnetically modulated microwave absorption, Ginzburg-Landau parameter, polycrystalline YBa₂Cu₃O₇₋ₓ films, London penetration depth

Subject Categories

Thin films, Superconductors, Pulsed laser deposition


Electromagnetics and photonics


American Institute of Physics

Publication Date


Rights Information

Copyright 1991 American Institute of Physics.

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American Institute of Physics

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