Figure 1: Temperature dependence of the helimagnetic domain structure in FeGe.

(a) Schematic of the helimagnetic spin order and wave vector q. Colour-coded planes indicate wave fronts of the magnetization M that are defined by uniformly oriented spins. (b) MFM image in the helimagnetic state. q₁ and q₂ indicate two magnetic domains. Scale bar, 500 nm. (c,d) With increasing temperature, local variations are observed in the domain structure while the period of the helimagnetic order within domains is unaffected. (e) The magnetic contrast vanishes when approaching T_N.