Scientific Facilities

May 06, 2023
Stuttgart Center for Electron Microscopy(Peter A. van Aken)

The Stuttgart Center for Electron Microscopy (StEM), adds exceptional strength to the analytical capabilities of the MPI-FKF. The StEM possesses outstanding expertise in the field of transmission electron microscopy (TEM), scanning electron microscopy (SEM), focused ion-beam (FIB) applications, and methodology development. The StEM serves all institutional departments to provide researchers with ultrahigh-resolution electron-microscopy instrumentation at the forefront of technology. This is accomplished through a combination of high-precision and big-data acquisition, reinforced by computational modeling, data processing, and theory and methodology development.
The StEM is constantly exploring and expanding new capabilities made possible by recent technological developments such as monochromators, aberration correctors, energy filters, and fast pixelated direct electron detectors to provide application strategies for enhanced investigation capabilities of topical issues in materials physics and chemistry.
StEM currently has five TEMs, including two state-of-the-art aberration-corrected JEOL ARM200Fs and the unique Zeiss SESAM. The group also operates an SEM and a FIB/SEM as well as advanced sample preparation labs. The acquisition of a new atomic resolution multidimensional TEM from JEOL Ltd. funded by the Max Planck Society was ordered in 2020. The conversion and renovation of the laboratory space was completed at the end of 2022, and the new instrument, which is currently being installed, is expected to be in operation and available to the institute in the first quarter of 2023. more
Computer Service (Armin Burkhardt)

The Computer Service Groups runs the institute's central mail, print, software, backup and web servers, as well as file servers for the various departments and Max Planck Research Groups, most running the Linux operating system. Backup remains based on IBM Spectrum Protect (formerly Tivoli Storage Manager); currently the total backup data volume approaches 870 TB, 240 TB of which are archived data, the central Storage Area Network capacity is 800 TB. The estimated total number of desktops and data acquisition PCs remains around 750. Of these about 75% run Windows, 20% run Linux, the number of Macs is rising slowly.
The number of High Performance Computing (HPC) nodes rose to 551 and the number of computing cores to 26612 cores with 478 TB accumulated memory. The HPC associated electricity consumption rose to 170 kW. In reaction to this the server rooms 6B13 (infrastructure), 2E2 (High Performance Computing and Networking) were trimmed for energy and cooling efficiency using water cooled racks and reardoors. These installations use the 1.3 MW inhouse process cooling water plant. The achieved temperature spread of 209/25°C permits free (radiative) cooling throughout eight months of the year. During the current energy crisis the IT group was asked to reduce the energy consumption by 25%. This goal can be reached by shutdown of older hardware, energy optimisations on servers and HPC nodes and reorganisations as the opening the General Purpose Gauss cluster for the institute public thus reducing the number of group-internal computational resources.
For the Alavi group a distributed 1.75 PB filesystem accessible from the Stuttgart Campus as well as from the MP/CDF computing and data center in Garching is operational over a dedicated 10 GbE fiber connection. The 100 computing nodes of the Alavi department hosted at the MP/CDF were shut down to save energy as well as half of the compute nodes installed back in 2014 during the foundation of the Alavi group.
The Xen-virtualisation platform for central services was updated and relies now on a CEPH based distributed storage backend. The services can move freely between two locations in the main building and the new High Precision Lab in order to ensure High Availability of the services. The high availability storage is distributed over 3 locations.
A new Firewall and VPN remote access strategy was implemented together with significant changes in the institute's Identity Management (IdM). The groups focus here was to rely on open industry standards whereever possible to avoid customer lock-in. When needed, proprietary systems like Microsoft Active Directory were provisioned with external help from open sources like Open-LDAP in order to permit software and patch roll-out in Windows environments. These measures focus on the protection of the institute data and infrastructure while enabling scientists to access them from abroad. The international collaboration and the inherent non-locality of science make these tasks highly complex.
User training to detect and resist cyber attacks has been intensified. The rules for remote access have been tightened and 2-factor-authentication is under implementation more
X-Ray Diffraction (Robert Dinnebier)

The X-Ray Diffraction group provides scattering and diffraction measurements and analysis of powders using laboratory, synchrotron, and neutron sources, under ambient and non-ambient conditions. Research is focused on the determination of crystal structures, microstructural properties (strain, domain size, stacking faults), nanoscale structural states, and phase composition of condensed matter, along with methodological development within this area. Scientific cooperation is offered in all fields of routine and non-routine analysis. Special expertise in ab initio solution and refinement of crystal structures from powder diffraction data is provided. Long-term research projects deal with structure–property relationships of functional materials (e. g. thermochromic-, photochromic-, electronic-, magnetic-, and construction materials). The structures of corrosion phases found on heritage objects are determined to guide conservation methods. Disordered and nanostructured materials are characterized using total scattering and pair distribution function methodologies, e. g. for assessment of processing effects on the structure and stability of semicrystalline and amorphous polymers and active pharmaceutical ingredients. Reaction and transformation mechanisms are studied using in situ monitoring including solution-based and mechanochemical syntheses and gas loading of metal-organic frameworks (MOFs). Lectures and workshops on crystallography are offered and textbooks are written in regular intervals. more
Information Service CPT (Robin Haunschild)

The Central Information Service for the institutes of the Chemical Physical Technical (CPT) Section of the Max Planck Society offers database searches, which are too complex or demanding for end users, and provide access to information sources not included in the range of end user databases commonly accessible. Most important are the various field-specific literature and patent databases as well as the citation databases accessible via Web of Science and Scopus. Establishing impact data for research evaluation has become a major field of activity of the information service. The determination of meaningful indicators and the proper interpretation of citation impact data require some experience and sound background information. Research and publication activities in the newly emerging fields of bibliometrics and altmetrics address the need for such experience when using and interpreting citation data. more
Crystal Growth (Masahiko Isobe)

The Crystal Growth scientific facility aims to grow high quality single crystals from melt, solution or vapor, in order to investigate their interesting physical properties. The techniques used include the optical floating zone (OFZ) method, flux growth, chemical vapor transport (CVT), Bridgman and hydrothermal growth. In addition, growth under high-pressure conditions is available in collaboration with the Takagi department. Recently, an OFZ furnace under high gas pressure has been set up in collaboration with the Keimer department. The high-Tc-cuprate, YBa2Cu3O7-d, remains subject to continual interest for further studies of its superconductivity. The flux method has been used for the crystal growth of the cuprate. The CVT method has been used to grow crystals of Ta2NiSe5, which is a candidate for an excitonic insulator. Many experimental results have pointed to the excitonic character of the transition. However, it has become increasingly clear that the transition cannot be purely Excitonic, and that the actual situation is more complicated. The OFZ furnace under high gas pressure has been used for the nickelates project in collaboration with the Keimer department. The infinite-layer nickelate thin film, which is a new superconductor, is very interesting given the analogies to the high-Tc-cuprates. We have obtained crystals of several perovskite nickelate RNiO3 using the OFZ furnace under high oxygen gas pressure. The infinite layer nickelates have been prepared by reducing the obtained crystals with CaH2. However, the oxygen reduction process necessary to obtain the infinite layer structure ended up breaking the crystals. Nevertheless, the more metallic behavior of the broken crystals compared to that of the powder samples is closer to what was seen in thin films. more
Thin Film Technology (Gennady Logvenov)

The Thin Film Technology group provides expertise in synthesis, thermal treatment and characterization of complex oxide epitaxial thin films and heterostructures with high precision to all members of MPI-FKF. By using the pulsed laser deposition (PLD), ozone assisted molecular beam epitaxy (MBE) and reactive sputtering we synthesize different complex oxides including cuprates, manganates, nickelates, cobaltates, vanadates, ruthenates, iridates and many other. Our research interests are grouped into three categories: (i) the development of state-of-the-art instruments for novel oxide thin film deposition and defect control to ensure a material base suitable for the forefront research within MPI-FKF, (ii) physics and chemistry at oxide interfaces, (iii) the electronic devices based on novel oxides. The main customers are the researchers from the departments Keimer, Maier, and Takagi. The Thin Film Technology Facility group has executed the projects in close collaboration not only with research departments also with the Stuttgart Center for Electron Microscopy Facility that has ability for an atomic scale imaging of oxide heterostructures. In addition, we support other departments and projects with materials deposition such as metals (Au, Pt, Ti, Cr etc.) and insulators SiOx, TiO2, Al2O3 …), dry chemical etching, patterned contact fabrication, ultrasonic bonding and physical properties measurements such as thermoelectricity, resistivity, mutual inductance, X Ray Diffraction and Atomic Force Microscope. more
Interface Analysis (Ulrich Starke)

The Interface Analysis group investigates the atomic and electronic structure of solid-solid and gas-solid interfaces. Using electron spectroscopy, diffraction, scanning probe microscopy and secondary ion mass spectrometry (SIMS), atomic geometry, electronic band structure and chemical composition and bonding are determined. Thin films and buried interfaces are accessible by sputtering and cleaving techniques. Experimental methods include time-of-flight SIMS to quantify the chemical composition of surfaces, films and interfaces. Chemical and electronic properties are investigated by electron spectroscopy. Photoemission electron microscopy (PEEM), in momentum microscopy mode completes the electronic structure investigations with high energy, spatial and momentum resolution. Atomic structure is analyzed by low-energy electron diffraction (LEED). The group’s research covers ultrathin films of novel materials such as graphene and other 2D-materials, in particular, graphene layers grown on silicon carbide (SiC). Material growth, heterojunctions, molecular adsorbates and metallization are investigated on an atomic level. Quasi-free standing, homogeneous, large area epitaxial graphene films are grown on SiC. Their electronic structure is tailored on an atomic level by doping and intercalation. The graphene valence bands are analyzed using angle-resolved photoelectron spectroscopy (ARPES) and k-space microscopy. Beamtimes at various synchrotron facilities are used in addition. more
Nanostructuring Lab (Jürgen Weis)

In 2011, the cleanroom facility of the von Klitzing department became part of the newly established Scientific Facility Nanostructuring Lab (NSL). NSL customers are coming from the Institute, the MPI of Intelligent Systems, and the University of Stuttgart. Under class-10 cleanroom conditions with stable room humidity and temperature, samples are processed by students or in service by the NSL team using photolithography, dry and wet etching, and material deposition under vacuum. For the fabrication of structures down to 10 nm – on small but also large area, two electron-beam lithography systems using acceleration voltages up to 100 kV are available. A focused ion beam system allows to cut and to sculpture samples. State-of-the-art scanning electron microscopes, including analytic tools like EBIC, EDX, EBSD and scanning probe microscopy inside the SEM chamber, allow the characterization to nanometer scale. A vacuum cluster connects plasma-enhanced atomic layer deposition and plasma-enhanced etching. At present, we focus to exclude the exposure of samples to oxygen, water and humidity during characterization and processing.
A small group of Ph.D. and Master students develops and operates a unique scanning probe microscope at 40 mK with a linear array of single-electron transistors and Hall sensors as probes. Recently, we have measured the Hall potential profile and therefore the current distribution in several fractional quantum Hall regimes.
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