Beyond Gallium: FIB based local materials property tuning with advanced ion sources

Gas Field Ion Source (GFIS) based Helium Ion Microscopy (HIM) is providing best
resolution Nobel gas focused ion beam (FIB) based imaging and nanofabrication capabilities [1,
2]. Liquid Metal Alloy Ion Source (LMAIS) based FIBs, on the other hand enable the nanoscale
modification of the morphology and the elemental composition of materials [3]. I will address
in particular low on fluence modification of materials properties with only negligible material
removal. Examples in the part will include the modification magnetic, superconducting,
electrical and optical properties in metals, semiconductors and 2D materials. I will show how
the HIM can be used to create arbitrary shaped nano-magnets [4] and tailor their magnetic
properties, with minimal morphological modifications. We use a set of in-situ probes to follow
the change of the magnetic properties during irradiation to allow optimized fluence delivery [5].
Similarly, we can use the probes to characterize transistors build from 2D materials and
follow the change of their electrical properties during ion beam irradiation. However, also
beams of other elements are useful for crating new functionality on the nanometer scale. I
will present very recent results on the application of Dy and Co LMAIS FIB to tune the spin
transport properties of magnetic materials.
Part of this work has been performed in the framework of COST Action FIT4NANO
(CA19140) and the BMBF projects ZF4330905AB9 and ZF4330902DF7.