FIB-SEM Protocol for High-Resolution Imaging Combined with EDX Analysis of Cement-Based Materials with Minimized Damage

The application of focused ion beam-scanning electron microscopy (FIB-SEM) in materials science is a powerful tool for high-resolution three-dimensional imaging. However, similar to biological specimens, the use of FIB-SEM in combination with energy-dispersive X-ray spectroscopy (EDX) on water-containing mineral phases like calcium-silicate-hydrate (C-S-H) and portlandite (CH) presents unique challenges. At room temperature, the interaction between the electron beam and hydrated minerals can induce damage due to the prolonged irradiation time on a small surface, limiting the applicability of this technique for studying cement-based materials. However, the damage caused by the method is rarely mentioned in the literature. This is highlighting the need for optimized preparation and application protocols with a focus to minimize specimen damage while achieving high-resolution imaging and EDX for chemical characterization. Furthermore, in the present study a larger volume of interest (VOI, 20 x 20 x 20 µm³) is investigated, representing a significant increase in scale compared to our previous FIB-SEM studies (10 x 10 x 10 µm³).