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arXiv · 1204.5693

Susceptibility anisotropy in an iron arsenide superconductor revealed by x-ray diffraction in pulsed magnetic fields

J. P. C. Ruff·J. -H. Chu·H. -H. Kuo·R. K. Das·H. Nojiri·I. R. Fisher·Z. Islam
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Abstract

In addition to unconventional high-Tc superconductivity, the iron arsenides exhibit strong magnetoelastic coupling and a notable electronic anisotropy within the a-b plane. We relate these properties by studying underdoped Ba(Fe{1-x}Co{x})2As2 by x-ray diffraction in pulsed magnetic fields up to 27.5 Tesla. We exploit magnetic detwinning effects to demonstrate anisotropy in the in-plane susceptibility, which develops at the structural phase transition despite the absence of magnetic order. The degree of detwinning increases smoothly with decreasing temperature, and a single- domain condition is realized over a range of field and temperature. At low temperatures we observe an activated behavior, with a large hysteretic remnant effect. Detwinning was not observed within the superconducting phase for accessible magnetic fields.

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J. P. C. Ruff, J. -H. Chu, H. -H. Kuo, R. K. Das, H. Nojiri, I. R. Fisher, Z. Islam. 2012-04-25. Susceptibility anisotropy in an iron arsenide superconductor revealed by x-ray diffraction in pulsed magnetic fields. https://doi.org/10.1103/physrevlett.109.027004

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