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arXiv · 0907.3973

Absence of large nanoscale electronic inhomogeneities in the Ba(Fe1-xCox)2As2 pnictide

Y. Laplace·J. Bobroff·F. Rullier-Albenque·D. Colson·A. Forget
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Abstract

75As NMR and susceptiblity were measured in a Ba(Fe1-xCox)2As2 single crystal for x=6% for various field H values and orientations. The sharpness of the superconducting and magnetic transitions demonstrates a homogeneity of the Co doping x better than +-0.25%. On the nanometer scale, the paramagnetic part of the NMR spectra is found very anisotropic and very narrow for H//ab which allows to rule out the interpretation of Ref.[6] in terms of strong Co induced electronic inhomogeneities. We propose that a distribution of hyperfine couplings and chemical shifts due to the Co effect on its nearest As explains the observed linewidths and relaxations. All these measurements show that Co substitution induces a very homogeneous electronic doping in BaFe2As2, from nano to micrometer lengthscales, on the contrary to the K doping.

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Y. Laplace, J. Bobroff, F. Rullier-Albenque, D. Colson, A. Forget. 2009-07-23. Absence of large nanoscale electronic inhomogeneities in the Ba(Fe1-xCox)2As2 pnictide. https://doi.org/10.1140/epjb/e2009-00414-x

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