NMR Study of Over-doped NaFe1-xCuxAs Single Crystals

ORAL

Abstract

We present our NMR study of over-doped pnictide NaFe1-xCuxAs, which has been demonstrated to be a possible Mott insulator near x ≈ 0.5 [1,2]. Our NMR spectra show two inequivalent 23Na sites due to Cu dopants. Both 23Na and 75As NMR spectra show a possible formation of stripe-like ordering of Fe and Cu in the 35% and 50% Cu-doped samples. The large Curie-Weiss-like magnetization due to impurity effects results in strongly inhomogeneous field distribution through out the heavily Cu-doped samples, significantly broadening both 23Na and 75As spectra. Our 23Na spin-lattice relaxation data shows an enhanced relaxation rate in regions close to Cu dopants.

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Presenters

  • Yizhou Xin

    Northwestern University, Northwestern Univ

Authors

  • Yizhou Xin

    Northwestern University, Northwestern Univ

  • Jeongseop Lee

    Northwestern Univ

  • Ingrid Stolt

    Northwestern Univ

  • William Halperin

    Northwestern Univ, Physics and Astronomy, Northwestern Univ, Physics, Northwestern University

  • Yu Song

    University of California Berkeley, Univ of California - Berkeley

  • Weiyi Wang

    Rice Univeristy, Rice University

  • Pengcheng Dai

    Physics and Astronomy, Rice University, Rice University, Physics, Rice University, Rice Univeristy

  • Chongde Cao

    Northwestern Polytechnical Univeristy

  • Arneil Reyes

    National High Magnetic Field Laboratory, Florida State University, NHMFL, Florida State University, National High Magnetic Field Laboratory