Automated Phase Plate Application In Transmission Electron Microscopy (English shop)

Preview

Table of Contents, PDF (50 KB)
Extract, PDF (250 KB)

Transmission electron microscopy is an essential tool to determine the structure of biological and material-science samples. A majority of the studied specimen are phase objects, i.e. they impose a small distortion on the phase on the traversing electron wave. To visualize this signal, conventional transmission electron microscopy needs to apply intended lens aberrations, which results in distorted images.

Phase plate microscopy offers an alternative possibility to generate phase contrast without relying on the lens aberrations. However, the delicate alignment of the phase plates and their quick degeneration prevent their routine application.

In this work, approaches for automating the phase plate alignment are developed. To further improve the applicability, different means to reduce the so-called cut-on effect are evaluated. For that, the characteristics of a prototype instrument especially constructed to solve the cut-on problem are assessed and the properties of a new dynamic imaging mode examined in a theoretical study and by simulation.
The applicability of the approach is demonstrated on beam-sensitive samples using the developed automation routines.