Hall Effect and Resistivity in Epitaxial MnSi Thin Films Under Ambient and High Pressure

Thin film MnSi has been epitaxially grown on Si(111) substrate and investigated in terms of magnetoresistance and Hall measurements under applied hydrostatic pressure up to 2.58 GPa. Although the behavior of the thin films is qualitatively similar to bulk material, at a high pressure above 2 GPa, an additional magnetic ordering occurs, resulting in a reduction of the potential scattering by spin fluctuations. This ordering is stabilized at the applied pressure showing visible effects in the magnetotransport data. Comparing the behavior of thin films with the bulk material under pressure, it seems quite likely that this additional ordering is of skyrmionic nature, which has as yet not been unambiguously evidenced in epitaxial B20 thin films on a substrate under ambient pressure.