Three-Dimensional Microstructural Characterization Using Focused Ion Beam Tomography

This article reviews recent developments and applications of focused ion beam (FIB) microscopes for three-dimensional (3D) materials characterization at the microscale through destructive serial sectioning experiments. Precise ion milling—in combination with electron-optic—based imaging and surface analysis methods—can be used to iteratively section through metals, ceramics, polymers, and electronic or biological materials to reveal the true size, shape, and distribution of microstructural features. Importantly, FIB tomographic experiments cover a critical size-scale gap that cannot be obtained with other instrumentation. The experiments encompass material volumes that are typically larger than 1000 μm3, with voxel dimensions approaching tens of nanometers, and can contain structural, chemical, and crystallographic information. This article describes the current state of the art of this experimental methodology and provides examples of specific applications to 3D materials characterization.