Maximum diameter of the rod-shaped specimen for transmission electron microtomography without the “missing wedge”

In our recent study, the complete rotation of a rod-shaped specimen during transmission electron microscopy (TEM) has been successfully carried out, yielding a truly quantitative three-dimensional (3D) structure of a ZrO2/polymer nano-composite. This result allows the further development of transmission electron microtomography (TEMT) for materials science. The diameter of the rod-shaped specimen was about 150 nm, which may not be statistically large enough to evaluate structural parameters, e.g., volume fraction of Zr nano-particles. Thus, it is preferable to image rods with larger diameters in 3D. In this study, several rod-shaped specimens whose diameters ranged from 150 to 530 nm were subjected to the “distortion-free TEMT”. The maximum diameters, l, observable under 200 and 300 kV-TEMTs were, respectively, 460–470 and 600–670 nm (corresponding the maximum relative diameters, l / λ ( λ : mean free path), were ca. 2.2 and 2.7–3.0).