The FELMI-ZFE Institute for Electron Microscopy and Nanoanalysis in Graz has published an innovative paper on Magnetic Force Microscopy (MFM) and the new method to make magnetic cantilever tips by focused electron beam induced deposition (FEBID).
MFM represents a valuable extension of atomic force microscopy (AFM), whereby cantilevers with functional coatings are currently primarily used for the investigation of magnetic surface features. Despite their proven usefulness, the additional films inevitably lead to an increase in the tip radii, which reduces the lateral resolution. To overcome these limitations, the FELMI-ZFE researchers present a novel approach involving additive direct writing of 3D magnetic nanostructures by focused electron beam induced deposition (FEBID) using a HCo3Fe(CO)12 precursor.
It starts with the identification of an optimal 3D design for functional magnetic structures in order to subsequently optimize the most important process parameters acceleration voltage and beam current and also evaluates the post-growth process. This enables the manufacturing of high-crystalline nano-tips with minimal surface contamination and tip radii of less than 15 nm.
In a next step, these cantilever tips are compared with commercial products. The results show not only outstanding performance in MFM measurements but also virtually loss-free behavior even after almost 8 hours of continuous operation. Remarkably, no drop in performance is observed even after more than 12 months of storage under ambient conditions, which underlines the sustained high performance of the developed nano-tips.
To test these novel cantilevers, they used the unique functions of the FusionScope, such as the practical profile view. This enables both precise positioning of the AFM and observation of the interaction of the tip with the sample surface. The study demonstrates the expertise and success of the researchers and confirms the central role of the FusionScope in the further development of scientific research at the nanoscale.

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