%0 Journal Article
%T Susceptibility anisotropy in an iron arsenide superconductor revealed by x-ray diffraction in pulsed magnetic fields
%A J. P. C. Ruff
%A J. -H. Chu
%A H. -H. Kuo
%A R. K. Das
%A H. Nojiri
%A I. R. Fisher
%A Z. Islam
%J Physics
%D 2012
%I arXiv
%R 10.1103/PhysRevLett.109.027004
%X 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.
%U http://arxiv.org/abs/1204.5693v1