Revealing 3D magnetization of thin films with soft X-ray tomography: magnetic singularities and topological charges

The knowledge of how magnetization looks inside a ferromagnet is often hindered by the limitations of the available experimental methods which are sensitive only to the surface regions or limited in spatial resolution. Here we report a vector tomographic reconstruction based on soft X-ray transmission microscopy and magnetic dichroism data, which has allowed visualizing the three-dimensional magnetization in a ferromagnetic thin film heterostructure. Different non-trivial topological textures have been resolved and the determination of their topological charge has allowed us to identify a Bloch point and a meron-like texture. Our method relies only on experimental data and might be of wide application and interest in 3D nanomagnetism.Alba light source is funded by the Ministry of Research and Innovation of Spain and by the Generalitat de Catalunya and by European FEDER funds. This project has been supported by Spanish MINECO under grant FIS2016-76058 (AEI/FEDER, EU) and grant PID2019-104604RB/AEI/10.13039/501100011033. A.H.-R. and S.MV. acknowledge the support from European Union’s Horizon 2020 research and innovation program under Marie Skłodowska-Curie grant ref. H2020-MSCA-IF-2016-746958.Peer reviewe