Extended skyrmion lattice scattering and long-time memory in the chiral   magnet Fe$_{1-x}$Co$_x$Si
  Small angle neutron scattering measurements on a bulk single crystal of the doped chiral magnet Fe$_{1-x}$Co$_x$Si with $x$=0.3 reveal a pronounced effect of the magnetic history and cooling rates on the magnetic phase diagram. The extracted phase diagrams are qualitatively different for zero and field cooling and reveal a metastable skyrmion lattice phase outside the A-phase for the latter case. These thermodynamically metastable skyrmion lattice correlations coexist with the conical phase and can be enhanced by increasing the cooling rate. They appear in a wide region of the phase diagram at temperatures below the $A$-phase but also at fields considerably smaller or higher than the fields required to stabilize the A-phase. 
L. J. Bannenberg, K. Kakurai, F. Qian, E. Leli\`evre-Berna, C. D.   Dewhurst, Y. Onose, Y. Endoh, Y. Tokura, and C. Pappas
cond-mat.mtrl-sci