The aim of this tender is to procure a Scanning Transmission Electron Microscope (STEM), in accordance with the terms of reference and tender documents

As one of 18 centres of the Helmholtz Association, HZB employs around 1,200 people and has a total budget of around 150 million euros. HZB works closely with non-university research institutions, universities and universities of applied sciences, with a focus on the greater Berlin-Brandenburg area.

For research on the structure and function of matter, HZB operates the electron storage ring BESSY II, which generates highly brilliant synchrotron radiation from the terahertz to the X-ray range. The facility is used for the study of matter and has highly specialized sample environments. Here, experiments can be carried out under the most demanding conditions, e.g. high magnetic fields, low temperatures, high pressures. The further development of these unique instruments as well as the application and teaching of new techniques are among the main tasks of the center. With its user service, HZB provides around 3,000 external scientists (from 35 countries to date) with access to the measurement methods, some of which are unique.

HZB operates two other large-scale facilities for external institutions: an accelerator for Charité that generates proton beams for eye tumor therapy (at the LMC campus, Wannsee) and the Metrology Light Source, a storage ring optimized for calibration purposes for the Physikalisch-Technische-Bundesanstalt (at the WCRC in Adlershof).

The realization of a sustainable energy supply is a central and urgent issue of this decade. Research is faced with the challenge of developing sustainable approaches to solving the energy issue. In order to make a significant contribution to this, the CATLAB project was recently launched, which aims to develop novel thin-film catalyst materials for a green hydrogen economy and efficient energy conversion.

CATLAB is a joint initiative of HZB, the two Max Planck Institutes, the Fritz Haber Institute (FHI) - Institute for Chemical Energy Conversion, industry and the Berlin universities. In addition, there is a long-standing cooperation partnership between HZB and FHI in the implementation of synchrotron experiments.

Inhomogeneities in the surface and volume structure as well as the chemical composition of a heterogeneous catalyst have a significant influence on its functionality and reaction mechanism. These deviations, which represent deviations from the ideal crystal structure, are not accessible with integral methods, as they average over the entire structure. Estimates have shown that in some highly active systems, less than 1% of the accessible surface is active. For an understanding-based research approach, these structures must be identified and quantified. This identification includes not only the determination of the local structures in the original state, but also during and after catalysis. This approach is important because catalysts change dynamically under reaction conditions. This information can be used to create new structure-property relationships, which will make it possible to tailor active interfaces.

Such a research approach is of paramount importance, especially in view of the dominant role of heterogeneous catalysis in renewable energy storage and conversion technologies. In order to structurally support the ever-expanding libraries of materials nanoengineering strategies, there is a great need to classify local structures at the atomic level. Ultimately, this will allow a detailed description of the catalytically active component. Examples of structural inhomogeneities or local structures include the geometric and electronic decoupling of surface and volume structures or the description of defects. Modern aberration-corrected analytical (scanning) transmission electron microscopes (STEM) are unique instruments to detect the local chemical and physical properties of functional solids, not only in a vacuum, but also under working conditions.

Therefore, a new characterization platform with high spatial resolution is necessary to investigate the local geometric and electronic structure as well as compositional differences of heterogeneous powder and thin-film catalysts.

In particular, the following techniques are needed to characterize and describe this class of materials in detail and efficiently:

- Energiedispersive Röntgenspektroskopie (EDX),

- Elektronenenergieverlustspektroskopie (EELS),

- Elektronenbeugung (ED),

- imaging techniques (cameras and detectors) that make it possible to penetrate the geometric structure of the solid down to the atomic level with parallel illumination and by means of a focused electron beam.

- In addition, TEM holders are required that are adapted to the respective problem.

- The microscope should be capable of automation. Metadata should be extractable.

Furthermore, a service/maintenance contract is to be concluded for a maximum of 48 months.