Anisotropic spin fluctuations and multiple superconducting gaps in hole-doped Ba0.72K0.28Fe2As2: NMR in a single crystal

Kazuaki Matano, Z. Li, G. L. Sun, D. L. Sun, C. T. Lin, Masanori Ichioka, Guo-Qing Zheng

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Abstract

We report the75As-NMR study on a single crystal of the hole-doped iron-pnictide superconductor Ba0.72K0.28Fe 2As2(Tc = 31.5 K). We find that the Fe antiferromagnetic spin fluctuations are anisotropic and are weaker compared to underdoped copper-oxides or cobalt-oxide superconductors. The spin lattice relaxation rate 1/T1 decreases below Tc with no coherence peak and shows a stepwise variation at low temperatures, which is indicative of multiple superconducting gaps, as in the electron-doped Pr(La)FeAsO 1-xFx. Furthermore, no evidence was obtained for a microscopic coexistence of a long-range magnetic order and superconductivity.

Original languageEnglish
Article number27012
JournalEPL
Volume87
Issue number2
DOIs
Publication statusPublished - Jul 2009

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nuclear magnetic resonance
Group 5A compounds
cobalt oxides
single crystals
copper oxides
spin-lattice relaxation
superconductivity
iron
electrons

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Anisotropic spin fluctuations and multiple superconducting gaps in hole-doped Ba0.72K0.28Fe2As2 : NMR in a single crystal. / Matano, Kazuaki; Li, Z.; Sun, G. L.; Sun, D. L.; Lin, C. T.; Ichioka, Masanori; Zheng, Guo-Qing.

In: EPL, Vol. 87, No. 2, 27012, 07.2009.

Research output: Contribution to journalArticle

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