We present Hall-effect measurements on MnSi/Si(111) epilayers and find an anomalous Hall contribution that is significantly smaller than that in bulk crystals, which enables the observation of an additional contribution to the anomalous signal previously overlooked in MnSi. Our measurements indicate the signal is not due to skyrmions in MnSi thin films, which are absent in out-of-plane fields, but rather are the result of scattering from the cone phase. The absence of magnetic contrast in the transmission electron microscopy (TEM) measurements is consistent with this interpretation [T. L. Monchesky et al., Phys. Rev. Lett. 112, 059701 (2014)]. We provide a method to model TEM images of skyrmion lattices to determine the conditions necessary for their observation in other B20 epilayers with an anisotropy that is favorable to their formation.

• Received 22 September 2014
• Revised 17 November 2014

DOI:https://doi.org/10.1103/PhysRevB.90.224419