In recent years, the use of the focused-ion beam (FIB) microscope has become widespread in the areas of materials processing and materials characterizaation. Although initial commercialization of FIB instruments was driven by applications in the semiconductor industry, recently the FIB has emerged as a broad characterization tool capable of imaging, material removal and material deposition. This combination makes it a useful instrument for applications ranging from site-specific sample preparation for transmission electron microscopy1 to thin-film head manufacturing. However, since the interaction of a high-energy ion beam (e.g., 30 keV Ga) with a solid inevitably produces implantation damage and the possibility of other effects such as grain growth, dislocation motion or degradation of magnetic properties , it is important to quantify to what extent the material under examination has been modified. Simple TRIM simulations may provide an estimation of the implantation level and depth to which ions will travel into a solid, but these results may not be accurate because FIB milling is not a static situation.

In order to investigate Ga implantation depth, concentration and possible grain growth effects, three circular regions on a 500 nm thick electroplated Ni-80 at.% Fe film were milled using 30 keV Ga ions at three different beam currents, Fig. 1.