NMR investigation of spin correlations in BaCo2As2

K. Ahilan; T. Imai; A. S. Sefat; F. L. Ning

doi:10.1103/PhysRevB.90.014520

NMR investigation of spin correlations in BaCo2As2

Superconductivity 2015-06-22 v1 Strongly Correlated Electrons

Authors: K. Ahilan , T. Imai , A. S. Sefat , F. L. Ning

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Abstract

We use NMR techniques to investigate the magnetic properties of BaCo2As2 single crystals, the non-superconducting end member of the Co-substituted iron-pnictide high Tc superconductor Ba(Fe1-xCox)2As2 with x = 1. We present 75As NMR evidence for enhancement of low frequency spin fluctuations below ~ 100 K. This enhancement is accompanied by that of static uniform spin susceptibility at the wave vector q = 0, suggesting that the primary channel of the spin correlations is ferromagnetic rather than antiferromagnetic. Comparison between the NMR Knight shift 75K and bulk susceptibility chi(bulk) data uncovers the presence of two separate components of spin susceptibility with distinct temperature dependences, presumably because multiple electronic bands crossing the Fermi energy play different roles in the electronic properties of BaCo2As2.

Keywords

NMR spectroscopy spin correlations BaCo2As2 iron-pnictide ferromagnetic fluctuations Knight shift spin susceptibility multi-band effects

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@article{arxiv.1407.2750,
  title  = {NMR investigation of spin correlations in BaCo2As2},
  author = {K. Ahilan and T. Imai and A. S. Sefat and F. L. Ning},
  journal= {arXiv preprint arXiv:1407.2750},
  year   = {2015}
}

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NMR investigation of spin correlations in BaCo2As2

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