Advances in 3D focused ion beam tomography
This article summarizes recent technological improvements of focused ion beam tomography. New in-lens (in-column) detectors have a higher sensitivity for low energy electrons. In combination with energy filtering, this leads to better results for phase segmentation and quantitative analysis. The quality of the 3D reconstructions is also improved with a refined drift correction procedure. In addition, the new scanning strategies can increase the acquisition speed significantly. Furthermore, fast spectral and elemental mappings with silicon drift detectors open up new possibilities in chemical analysis. Examples of a porous superconductor and a solder with various precipitates are presented, which illustrate that combined analysis of two simultaneous detector signals (secondary and backscattered electrons) provides reliable segmentation results even for very complex 3D microstructures. In addition, high throughput elemental analysis is illustrated for a multi-phase Ni-Ti stainless steel. Overall, the improvements in resolution, contrast, stability, and throughput open new possibilities for 3D analysis of nanostructured materials.