Local antiferromagnetic correlations in the iron pnictide superconductors LaFeAsO{1-x}F{x} and Ca(Fe,Co)2As2 as seen via normal-state susceptibility

R. Klingeler; N. Leps; I. Hellmann; A. Popa; U. Stockert; C. Hess; V. Kataev; H. -J. Grafe; F. Hammerath; G. Lang; G. Behr; L. Harnagea; S. Singh; B. Buechner

arXiv · 0808.0708

Local antiferromagnetic correlations in the iron pnictide superconductors LaFeAsO{1-x}F{x} and Ca(Fe,Co)2As2 as seen via normal-state susceptibility

R. Klingeler·N. Leps·I. Hellmann·A. Popa·U. Stockert·C. Hess·V. Kataev·H. -J. Grafe·F. Hammerath·G. Lang·G. Behr·L. Harnagea·S. Singh·B. Buechner

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Abstract

We have studied the interplay of magnetism and superconductivity in LaFeAsO$_{1-x}$F$_x$ and Ca(Fe$_{1-x}$Co$_x$)$_2$As$_2$. While antiferromagnetic spin density wave formation is suppressed and superconductivity evolves, all samples show a doping independent strong increase of the normal state susceptibility upon heating which appears a general feature of iron pnictides. The data provide evidence for robust local antiferromagnetic correlations persisting even in the superconducting regime of the phase diagram.

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R. Klingeler, N. Leps, I. Hellmann, A. Popa, U. Stockert, C. Hess, V. Kataev, H. -J. Grafe, F. Hammerath, G. Lang, G. Behr, L. Harnagea, S. Singh, B. Buechner. 2009-11-13. Local antiferromagnetic correlations in the iron pnictide superconductors LaFeAsO{1-x}F{x} and Ca(Fe,Co)2As2 as seen via normal-state susceptibility. https://arxiv.org/abs/0808.0708

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