Transmission Electron Microscopy

Transmission Electron Microscopy (TEM) and related techniques enable the imaging (2D or 3D) and atomic-scale structural and chemical analysis of very thin samples.

An optical microscope uses a beam of light and glass lenses, whereas electron microscopes use a beam of electrons and magnetic lenses. Thanks to the much shorter wavelength of electrons, the electron microscopes to provide a much better resolution.

Within transmission electron microscopes, the electron beam passes through the sample at high speed. The interaction between the electrons and the sample produces radiation that is transcribed into an image which can be viewed on a screen.

Our TEM instruments

Nant’Themis

Hitachi H9000NAR

To know the rates and have access to our TEM microscopes, please contact us by email:

  • These microscopes are also part of CIMEN (Centre Interdisciplinaire de Microscopie Électronique de Nantes).
  • Collaboration with Prof. Bruce Dunn’s team (University of California, Los Angeles) to develop fast-charging battery materials. TEM microscopy can be used to validate structural hypotheses obtained on a larger scale.

Examples and applications

“By way of comparison, it’s so powerful that it could be used to analyze what a tennis ball is made of on the Moon… from Earth! This is a real technological breakthrough in the world of microscopy, opening up new prospects for knowledge and innovation.”

Philippe Moreau

To increase the use of electric vehicles, batteries must recharge in just a few minutes, with no loss of capacity. One solution is to replace the negative graphite electrodes used in Li-ion batteries with materials based on transition metal oxides.

In this study, the hexagonal tungsten bronze Cs0.5Nb2.5W2.5O14 and its protonated derivative were characterized by TEM. High-resolution STEM images and associated atomic-scale mappings highlighted that:

  1. half of the Cs cations are extracted from the Cs0.5Nb2.5W2.5O14 structure, mainly in the heptagonal channels, to form the compound H0.25Cs0.25Nb2.5W2.5O14
  2. there is a cationic ordering at the Nb and W sites, which means a higher specific capacity of the protonated material compared to its equivalent before ion exchange.

Left, experimental HAADF-STEM images of Cs0.5Nb2.5W2.5O14 (top) and H0.25Cs0.25Nb2.5W2.5O14 (bottom), with simulated images (Dr Probe software). Right, matching EDX maps (Cs: yellow, Nb: red, W: blue).

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