Resistivity, Hall effect, and anisotropic superconducting coherence lengths of HgBa2CaCu2O6 thin films with different morphology

Herbert Richter, Wolfgang Lang (Corresponding author), Martin Peruzzi, Helmut Hattmannsdorfer, John Hay Durrell, Johannes David Pedarnig

Publications: Contribution to journalArticlePeer Reviewed

Abstract

Thin films of the high-temperature superconductor HgBa2CaCu2O6 have been prepared on SrTiO3 substrates by pulsed-laser deposition of precursor films and subsequent annealing in mercury-vapor atmosphere. The microstructural properties of such films can vary considerably and have been analyzed by x-ray analysis and atomic force microscopy. Whereas the resistivity is significantly enhanced in samples with coarse-grained structure, the Hall effect shows little
variation. This disparity is discussed based on models for transport properties in granular materials. We find that, despite of the morphological variation, all samples have similar superconducting properties. The critical temperatures Tc ∼ 121.2 K …122.0 K, resistivity, and Hall data indicate that the samples are optimally doped. The analyses of superconducting order parameter fluctuations in zero and finite magnetic fields yield the in-plane ξab(0) ∼ 2.3 nm …2.8 nm and out-of-plane ξc(0) ∼ 0.17 nm …0.24 nm Ginzburg–Landau coherence lengths at zero temperature. Hall measurements provide estimates of carrier scattering defects in the normal state and vortex pinning properties in the superconducting state inside the grains.
Original languageEnglish
Article number035031
Number of pages8
JournalSuperconductor Science & Technology
Volume34
Issue number3
Early online date8 Feb 2021
DOIs
Publication statusPublished - Mar 2021

Austrian Fields of Science 2012

  • 103033 Superconductivity

Keywords

  • mercury cuprate
  • superconductor
  • resistivity
  • Hall effect
  • order parameter fluctuations
  • coherence length
  • granular materials

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