The STEM group owns various equipment essentially dedicated to electron spectroscopy in Scanning Transmission Electron Microscopes (STEM). Most of them are adapted to and fitted with in house made instrumentation.
Developed by the NION company, the USTEM 200 is a C3 (spherical aberration of third order) and C5 corrected STEM received in 2011. It is fitted with a cold Field Emission Gun (CFEG) working from 40 keV to 200 keV. This allows to work with radiation sensitive (graphene...) material yet keeping a sub-atomic resolution, or to reach ultimate spatial resolutions with less radiation sensitive material (steels...). It is also fitted with an in house developed spectral-imaging and high speed, high sensitivity EELS detection system. Together with the good spectral resolution allowed by the FEG, it enables applications ranging from structure and chemical analysis of graphene like materials to atomically resolved electronic properties of interfaces of functional oxydes.
Our first Vacuum Generator HB 501 is fitted with a CFEG which enabled a high brigthness, a sub-nanometer spatial resolution and a good (less than 0.3 eV) spectral resolution, making it ideal for medium resolution analysis applications. Although bought 30 years ago, the VG cold has been constantly improved with in-house made instrumentation, such as enhanced scanning, spectral imaging and EELS capabilities. More recently, it has been fitted with a Nitrogen cooled stage and a high throughput cathodoluminescence system. All these improvement make the VG HB 501 still very competitive if not unique for the structural and chemical analysis of fragile materials, and for the nanooptics studies at the nanometer scale.
The VG Lumière ("light" in french) is a VG HB501 devoted to nanooptics and instrumentation development. It is fitted with a new in house made light injection devices for Electron Energy Gain Spectroscopy. No results yet, consult our theoretical prediction here!
The group is equiped with a computer cluster mainly dedicated to parallel quantum mechanical calculations of materials properties at the nanometre scale. The cluster consists of 39 computer nodes equiped with Xeon processors (a total of 644 computing cores), 96 Gb of RAM per node and it runs under the Rocks cluster distribution.