Tunneling break-junction spectroscopy on the superconductor NdFeAs(O 0.9F0.1)

Toshikazu Ekino, Akira Sugimoto, Hirotaka Okabe, Kazuhiro Shohara, Ryuichi Ukita, Jun Akimitsu, Alexander M. Gabovich

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Tunnel break-junction method has been adopted to study polycrystalline samples of iron-oxypnictide superconductor NdFeAs(O0.9F 0.1) with Tc=48K. Measurements were carried out at 4.2 K. Break-junction (BJ) conductance versus voltage curves showed gap-edge peaks with the peak-to-peak distances Vp-p=4Δ/e=28-40mV at 4.2 K, where 2Δ(T) is the superconducting energy gap, e>0 is the elementary charge. This yields 2Δ(0)=14-20meV, so that the gap ratio 2Δ(0)/kBTc is about 4.1±0.7,kB being the Boltzmann constant. This ratio implies strong-coupling superconductivity in the framework of Bardeen-Cooper-Schrieffer theory, being, however, much smaller than that for high-Tc copper oxides. This suggests a significant difference in the pairing mechanism between those classes of materials.

Original languageEnglish
JournalPhysica C: Superconductivity and its Applications
Volume470
Issue numberSUPPL.1
DOIs
Publication statusPublished - Dec 2010
Externally publishedYes

Fingerprint

Copper oxides
Superconductivity
Superconducting materials
Tunnels
Energy gap
Iron
Spectroscopy
Electric potential
spectroscopy
BCS theory
copper oxides
tunnels
superconductivity
iron
electric potential
curves

Keywords

  • Break-junction
  • Energy gap
  • Iron-oxypnictide superconductors
  • Tunneling

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology
  • Electronic, Optical and Magnetic Materials

Cite this

Tunneling break-junction spectroscopy on the superconductor NdFeAs(O 0.9F0.1). / Ekino, Toshikazu; Sugimoto, Akira; Okabe, Hirotaka; Shohara, Kazuhiro; Ukita, Ryuichi; Akimitsu, Jun; Gabovich, Alexander M.

In: Physica C: Superconductivity and its Applications, Vol. 470, No. SUPPL.1, 12.2010.

Research output: Contribution to journalArticle

Ekino, Toshikazu ; Sugimoto, Akira ; Okabe, Hirotaka ; Shohara, Kazuhiro ; Ukita, Ryuichi ; Akimitsu, Jun ; Gabovich, Alexander M. / Tunneling break-junction spectroscopy on the superconductor NdFeAs(O 0.9F0.1). In: Physica C: Superconductivity and its Applications. 2010 ; Vol. 470, No. SUPPL.1.
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