The ER-C provides external users from science and industry with access to the most powerful transmission electron microscopes available at the international level. External users will receive support from staff scientists and engineers at the ER-C, who will accompany them during demanding microscopic investigations, as well as during the required TEM specimen preparation and numerical data analysis. Fifty percent of the operation time of the ER-C's electron microscopes is reserved for external users who will formally have to apply for measuring time by submitting suitable research proposals. Measurement periods are allocated to external users according to scientific criteria considering a prioritisation laid down by a panel of reviewers appointed by the German Research Foundation. Details – also on how to submit a proposal – can be found at www.er-c.org as well as in the separate user rules and fee tables. In close cooperation with the in-house (S)TEM method development group, the ER-C offers efficient evaluation in order to enable external users to gain maximum information from the experimental images. This type of comprehensive user support takes on a key function in evaluating the reliability of the measured results. It is emphasised that the ER-C is not a service facility but a user centre, meaning that measurements are to be carried out by external users themselves with assistance and supervision of ER-C staff only. Service projects will not be considered for realisation.

The Tecnai G2 F20 is a versatile field emission transmission electron microscope ideally suited for studying a wide range of general and advanced solid state materials.This analytical instrument, which is equipped with a compustage-driven side-entry double-tilt goniometer stage and an assortment of specimen holders, is optimised for imaging at medium resolution or for performing elemental microanalysis. Electron energy loss spectroscopy (EELS), energy dispersive X-ray (EDX), and high angle annular dark-field (HAADF) signals for elemental microanalysis or spectral imaging can be collected either separately or simultaneously. Diffraction modes include convergent beam diffraction for three-dimensional structure information and micro-diffraction with a minimum probe size of 4 nm. For these purposes, the instrument is equipped with an EDAX r-TEM SUTW detector and a Gatan Tridiem 863P spectrometer coupled to integrated computer systems running analytical software. This system can acquire and quantify EDX and EELS spectra to generate elemental maps and perform microstructural imaging.

The FEI Titan 80-300 is a field emission gun transmission electron microscope equipped with an imaging spherical aberration corrector element. Characterised by an information limit well below 100 pm, the instrument was one of the first of a small number of sub ångström resolution transmission electron microscopes in the world operating at an acceleration voltage of 300 kV when commissioned in 2005. Digital images are to be taken with a Gatan 2k slow scan charged coupled device camera system. Specifications for the instrument operated under optimum conditions are given at the ER-C webservices.

The FEI Titan 50-300 PICO is a unique fourth generation field emission gun transmission electron microscope equipped with a high-brightness electron gun, a monochromator unit, and a Cs probe corrector. Furthermore, a Cs-Cc achro-aplanat image corrector and a post-column energy filter system are also on hand. Characterised by a TEM and STEM resolution of about 50pm at 300 kV, the instrument is one of the few chromatically-corrected high resolution transmission electron microscopes in teh world. Target specifications for the instrument are given at the ER-C webservices.

The JEOL 840A is a medium resolution scanning electron microscope used for conventional microstructure analyses. The instrument is designed for the analysis focusing on the physical and chemical microstructure of solid state materials allowing spatially resolved compositional analysis by an EDAX Genesis 200 X-ray emission spectroscopy system.

The FEI Titan 80-300 is a field emission gun scanning transmission electron microscope equipped with a probe spherical aberration corrector element along with an electron monochromator and a post column energy filter system. Characterised by a sufficient energy resolution, the instrument was one of the first of a small number of sub ångström resolution transmission electron microscopes in the world operating at an acceleration voltage of 300 kV when comissioned in 2006. Digital images are to be taken with a Gatan 2k slow scan charged coupled device camera system. Specifications for the instrument operated under optimum conditions are given at the ER-C webservices.

The Helios NanoLab 400S is a focused ion beam (FIB) system to be operated in dual beam mode, i.e. the fully digital field emission scanning electron microscope (SEM) is supplemented with focused ion beam technology and flipstage assembly, also coming with a retractable multi-region STEM detector. Platinum gas chemistry is the preferred metal deposition when a high deposition rate and precision of the depostion are required. Other deposition materials may, however, be selected. Specially designed for ultra high resolution TEM sample preparation, the instrument is also equipped with an integrated argon ion gun capable of yielding a dramatically increased sample quality coming along with the removal of amorphous specimen over- and underlayers covering conventionally prepared FIB samples. The system additionally allows for spatially resolved compositional analysis using the attached EDAX Genesis XM 4i X-ray microanalysis system.

Preparation of samples with large transparent areas and flat surfaces is a key element of electron microscopy. In particular, the interpretation of lattice images is often limited by the sample's geometry and their surface roughness. These parameters are largely determined by a particular sample preparation procedure. The increasing demand for microscopes with a spatial resolution approaching or even well below 1 Å strains the need to improve preparation techniques. It is for this reason that an increasing body of the work at the ER-C is devoted to the development of reliable and specialized thinning techniques. The centre provides services and support for sample preparation of TEM specimens. In total, three preparation rooms house equipment for procedures as cutting, mechanical polishing, ion milling, dry and wet etching and supporting optical microscopy. Samples can be fully prepared on-site or just finished off at the laboratories. Technical support and training is provided by staff members.

The FEI Titan G2 80-200 CREWLEY is a remotely operated field emission gun (scanning) transmission electron microscope equipped with a high-brightness Schottky field emission electron gun, a monochromator unit, a Cs probe corrector, a Super-X EDX system, an UltraScan 1000XP-P charge coupled digital camera, an on-axis bright-field/dark-field STEM detector as well as a Gatan Enfinium ER (model 977) spectrometer with DUAL EELS option allowing a simultaneous read-out of EDX and EELS signals at a speed of 1000 spectra per second. The Titan G2 80-200 CREWLEY is characterised by a STEM resolution of 80 pm and TEM information limit of 110 pm at 200 kV. Basic specifications for the instrument are given at the ER-C webservices.

The FEI Titan 60-300 is a field emission gun transmission electron microscope designed for electron holography and in situ TEM analyses. The instrument is equipped with a high-brightness electron gun, an objective lens with an ultra wide pole piece gap, an imaging spherical aberration corrector element, a post column energy filter system as well as a system of two electron biprisms. Digital images are to be taken with a Gatan 2k slow scan charged coupled device camera system. Specifications for the instrument operated under optimum conditions are given at the ER-C webservices.

The JEOL 7400F is a scanning electron microscope equipped with a cold field emission gun, primarily to be used for analysis where ultra high resolution is required. Furthermore, the instrument is fitted with a combined in-lens SE/BSE detector system as well as with two retractable SE- and BSE detectors. The 7400F is designed for the analysis of the physical and chemical microstructure of solid state materials at nanometre resolution. It additionally allows for spatially resolved compositional analysis when using the attached EDAX Genesis 2000 X-ray microanalysis system.

The image analysis facilities are designed to handle the computational needs of the users of the Ernst Ruska-Centre. Apart from hosting a number of commercial scientific software packages, staff are also engaged in the ongoing development of custom software solutions. The main focus of the application software is in the area of quantitative image analyses and numerical image assimilations, with the goal of extracting structural information from images taken with the centre's transmission electron microscopes.