The spatial resolution of low to intermediate voltage (up to 300 kV) microscopes has been significantly improved due to the advancement and extensive use of spherical aberration (Cs) correction systems in TEM.
By combining TEMs and aberration correction systems, new properties of materials can be discovered at the atomic scale.
The resolution provided by these microscopes is unprecedented. Using them during in situ experiments will allow for new discoveries when materials are subjected to external stimuli like high temperature or electric fields. The Protochips Fusion heating and electrical biasing system is developed to offer a low-drift and stable platform. This means that high-resolution imaging can be performed at high temperatures.
The experiment discussed below demonstrates how Fusion can realize the full resolution capability of TEM at high temperatures.
The experiment was conducted at the National Center for Electron Microscopy (NCEM) at the Lawrence Berkeley National Laboratory (LBNL) using the TEAM 0.5 TEM. The TEAM 0.5 is an FEI Titan and is equipped with a monochromator, a probe, a bright X-FEG electron source and image Cs correctors (CEOS).
Figure 1A shows the phase-contrast image of a gold nanoparticle at 600 oC. It shows the lattice fringes as well as the 5-fold faceting and twinning characteristics that are typical of gold nanoparticles. The Fast Fourier transform in Figure 1B shows that, at a temperature of 600 oC, a resolution of 0.6 Å was achieved. This indicates that Fusion does not limit the TEM resolution even at this high temperature because this value is very close to the TEM resolution limit of 0.5 Å.
Figure 1. Gold nanoparticle at 600 °C with the corresponding FFT
When the temperature was increased from room temperature to 600 oC during the study, the nanoparticles became highly dynamic. They started to coalesce, facets altered, and defects in the material began to move. It was possible to analyze these events with exceptional clarity at the atomic scale. This was due to the instrument’s stability, imaging and ability to record real-time videos.
In order to completely exploit their resolution capabilities for analytical and imaging analysis, conventional and aberration corrected TEMs require a low drift and stable heating system. The Fusion heating and electrical biasing system means that it is possible to image and analyze material at atomic resolution. It is also suitable for in situ heating of all materials.
This information has been sourced, reviewed and adapted from materials provided by Protochips.
For more information on this source, please visit Protochips.