The ASTEM Project:
Austrian Scanning Transmission Electron Microscope
The ASTEM is built by FEI Company, Eindhoven, The Netherlands.
It is a Titan3 TM 60-300 which consists of the following components:
- The ASTEM can be operated from 60 to 300 kV with a high-brightness electron gun (X-FEG) and an electron monochromator.
- The ASTEM provides a wide range of operating conditions and can be used for the study of all kind of materials and devices.
- The microscope is equipped with a Cs probe corrector for high resolution STEM-imaging (correction of spherical aberrations).
- A new energy-dispersive x-ray spectrometer (ChemiSTEM) for fast elemental mapping.
- A special energy-filter (Quantum filter, Gatan Inc, USA) for high energy-resolution EELS spectroscopy and EFTEM mapping.
- Electron tomography holders and software for atomic resolution 3D analysis.
Scientific and Technical Goals
The ASTEM is the only ultra-high performance in Austria. It provides a common platform for advanced material characterisation and is widely available to the materials and nanoscience community in Austria and Europe.
The microscope allows to address important scientific challenges such as:
- Direct atomic resolution of materials and devices
- Elemental analysis at atomic resolution
- Local electronic structure and bonding in interfaces and nanostructures
- Nanotomography of functional materials
- Nanometrology of semiconductor devices (inorganic and organic)
To meet these scientific challenges we have defined a number of technical issues:
- Spatial resolution of 0.07 nm for real-time structure imaging in the focused probe mode of operation (STEM)
- Engergy resolution for EELS-spectroscopy better 0.2 eV.
- High brightness electron source with 0.6 nA in a 0.1 nm probe.
Silicon-dumbbells in  STEM HAADF image
The ASTEM is jointly run by two institutions, the Graz Centre for Electron Microscopy of the Association for the Promotion of Electron Microscopy and Fine Structure Research and the Institute of Electron Microscopy and Nanoanalysis at the Graz TU.
The microscope is also embedded in local activities:
- Field of Expertise of the Graz TU: Advanced Materials Science
- Research field „Processes, Products and Materials“
- Members of the Association for the Promotion of Electron Microscopy and Fine Structure Research
- NAWI faculty of the Graz TU and the University of Graz
The FELMI-ZFE is a national research and user facility open to universities, research institutions and industry.