Dopant clustering, electronic inhomogeneity, and vortex pinning in iron-based superconductors

Can Li Song, Yi Yin, Martin Zech, Tess Williams, Michael M. Yee, Gen Fu Chen, Jian Lin Luo, Nan Lin Wang, E. W. Hudson, Jennifer E. Hoffman

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

We use scanning tunneling microscopy to map the surface structure, nanoscale electronic inhomogeneity, and vitreous vortex phase in the hole-doped superconductor Sr0.75K0.25Fe2As2 with Tc=32 K. We find that the low-T cleaved surface is dominated by a half Sr/K termination with 1×2 ordering and ubiquitous superconducting gap, while patches of gapless, unreconstructed As termination appear rarely. The superconducting gap varies by σ/Δ̄=16% on a ∼3 nm length scale, with average 2Δ̄/kBTc=3.6 in the weak-coupling limit. The vortex core size provides a measure of the superconducting coherence length ξ=2.3 nm. We quantify the vortex lattice correlation length at 9 T in comparison to several iron-based superconductors. The comparison leads us to suggest the importance of dopant size mismatch as a cause of dopant clustering, electronic inhomogeneity, and strong vortex pinning.

Original languageEnglish (US)
Article number214519
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume87
Issue number21
DOIs
StatePublished - Jun 27 2013

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Dopant clustering, electronic inhomogeneity, and vortex pinning in iron-based superconductors'. Together they form a unique fingerprint.

Cite this