Skyrmion lattice in the doped semiconductor<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Fe</mml:mtext></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Co</mml:mtext></mml:mrow><mml:mi>x</mml:mi></mml:msub><mml:mtext>Si</mml:mtext></mml:mrow></mml:math>

We report a comprehensive small angle neutron scattering study of the magnetic phase diagram of the doped semiconductor ${\text{Fe}}_{1\ensuremath{-}x}{\text{Co}}_{x}\text{Si}$ for $x=0.2$. For magnetic field parallel to the neutron beam we observe a sixfold intensity pattern under field cooling. The regime of the skyrmion lattice is highly hysteretic and extents over a wide temperature range as may be expected due to the site disorder of the Fe and Co atoms. Our study identifies ${\text{Fe}}_{1\ensuremath{-}x}{\text{Co}}_{x}\text{Si}$ as the second material in which a skyrmion lattice forms and establishes that skyrmion lattices exist also in doped semiconductors.