Understanding the magnetic phase diagram in capped MnSi thin films

Skyrmions are a topologically non-trivial magnetisation pattern that form in crystal structures whose broken inversion symmetry gives rise to the Dzyaloshinsky-Moriya interaction (DMI). Their robustness against thermal fluctuations make them ¿ in thin film form - attractive candidates for non-volatile memory devices. While bulk crystals of skyrmion materials have been well studied, the picture in thin films is still rather controversial due to added complications such as epitaxial strain, surface anisotropy, and magnetic biasing effects. We propose to use polarised neutron reflectometry to resolve the key features of the thin-film skyrmion phase diagram, investigating the twisting of magnetisation vectors that arises. In particular we hope to be able to unravel the influence of the interfaces on the magnetic state of the film in terms of their structural and magnetic effects.