We report a comprehensive small angle neutron scattering study (SANS) of the magnetic phase diagram of the doped semiconductor Fe_{1-x}Co_{x}Si for x=0.2 and 0.25. For magnetic field parallel to the neutron beam we observe a six-fold intensity pattern under field-cooling, which identifies the A-phase of Fe_{1-x}Co_{x}Si as a skyrmion lattice. The regime of the skyrmion lattice is highly hysteretic and extents over a wide temperature range, consistent with the site disorder of the Fe and Co atoms. Our study identifies Fe_{1-x}Co_{x}Si is a second material after MnSi in which a skyrmion lattice forms and establishes that skyrmion lattices may also occur in strongly doped semiconductors.
Cite
@article{arxiv.0903.2587,
title = {Skyrmion Lattice in a Doped Semiconductor},
author = {W. Münzer and A. Neubauer and S. Mühlbauer and C. Franz and T. Adams and F. Jonietz and R. Georgii and P. Böni and B. Pedersen and M. Schmidt and A. Rosch and C. Pfleiderer},
journal= {arXiv preprint arXiv:0903.2587},
year = {2010}
}