STOE: Your project carries an interesting name “Nordseekammer”, i.e., North Sea chamber. As you are located in Freiberg -far from the Ocean- where did the name come from?
Tina Weigel (TW): The funds for constructing the Nordseekammer came from a DESY (Deutsches Elektronen Synchrotron, Hamburg) project and when we were looking for a pleasant-sounding name for our new chamber, we wanted to give a nod to the chamber’s place of birth in the broadest sense.
STOE: When and how did plans for the Nordseekammer come about?
TW: Originally, the idea for a sample chamber allowing for more than one type of physical stimulation (e.g. temperature & voltage) came about when researching the MFP (migration-induced field-stabilized polar) phase  of SrTiO3 and developing the RSD (resonantly suppressed diffraction) method , which allows the measurement of atomic displacements with sub-picometer precision. The structure of the MFP phase of SrTiO3 was first observed in an XRD experiment with a subsequent confirmation of the polarity and pyroelectricity  of the phase by the Sharp-Garn method. To research this phase more precisely, a setup was required in which an electric potential could be run through the sample while simultaneously measuring X-ray diffraction.
STOE: What made you choose a STADIVARI as a platform for the Nordseekammer?
TW: We were looking for a diffractometer which can not only accommodate the large and heavy Nordseekammer (approx. 7kg and 24x24x18 cm) but is also able to drive it to various positions in the beam with a stage customized to carry the Nordseekammer. Thus, we needed to find a company who was willing to design a specialized diffractometer in collaboration with us.
During the young crystallographer’s lab meeting 2021 at STOE in Darmstadt we joined the tour through the factory and were inspired to start looking into the possibilities of working with a STADIVARI.
STOE: How much were you involved in the conceptualization of the changes in the STADIVARI?
TW: Besides myself also Prof. Matthias Zschornak and Dr. Hartmut Stöcker were involved in the Nordseekammer project. STOE involved us a great deal in the planning of the instrument, and we were in frequent contact to exchange ideas and test possible designs.
For example, we were originally considering using a Hexapod setup for the goniometer, however soon realized that its size would not allow us to install and connect the peripheral instruments required to run experiments with the Nordseekammer. Therefore, we collectively decided that using a customized stage built out of Huber parts would be the most spatially efficient option.
STOE: How long did the construction phase take?
TW: After acquiring the sufficient funds within the project R2R Battery (FKZ 03SF0542A) for our lab at the Zentrum für effiziente Hochtemperatur-Stoffwandlung (ZeHS), especially by the efforts of Prof. Dirk C. Meyer, the construction phase started in September 2022 and by August 2023 we had a fully operational machine in our lab. We were thrilled with how fast the custom STADIVARI was commissioned! Especially regarding that some hard and software components had to be specifically developed for this diffractometer. We also enjoy very much how easy it is to contact people at STOE if there are any questions on the software or instrument or requests for unforeseen upgrades.
STOE: What are your goals with this setup?
TW: First and foremost, we want to increase our possibilities for synchrotron measurements. Therefore, we test our samples for their quality and suitability for the planned experiments, but with the new setup we can also test which reflections are best observed for the current scientific question and estimate how they react, e.g., under an applied current.
Such experiments are not only valuable in saving synchrotron beam time but, when included in a beam time proposal, increase our chances of receiving the requested beam time.
Another project, which we are about to start, is the in-situ characterization of batteries under various physical probes. The batteries can be measured as full cells, half cells, coin cells or pouch cells and are produced in collaboration with various colleagues here at ZeHS. As the university of Freiberg has always had and still has close ties to mining applications, the battery research is aimed at producing batteries which can function under the harsh conditions of old mines or even for possible robotic mining applications in space.
For example, one of the projects revolves around aluminum battery cells, whose behavior under various temperatures is unknown.
STOE: What were your most significant findings so far with the Nordseekammer?
TW: The most important result with the Nordseekammer at the synchrotron was a study of the temperature dependence of the MFP phase. This was also our most complex experiment, where we really needed all the features of the chamber, such as applying an electric field, cooling and heating. For those interested, we describe the experiment in our publication about the Nordseekammer .
In the lab, we are still testing the possibilities of our STADIVARI together with the Nordseekammer. It is the first time for me to work with STOE software and I still have to learn a lot about the possibilities of the software. At the moment I am trying to reproduce our standard experiment with the formation of the MFP phase. I am looking forward to receiving the first batteries from my colleagues for in operando experiments with the STADIVARI.
STOE: What excites you most about the combination of the Nordseekammer and the STADIVARI?
TW: I love how much I can play around with the instrument! There is no standard measurement strategy and no standard sample geometry, I can define and decide everything myself on the hardware and even on the software side. This freedom is important for designing my measurements and is a lot of fun for me as well. The STADIVARI is basically a big, joyful playground for me!
Furthermore, it is exciting to see the research which people bring who cannot run their desired experiments on a standard instrument and hope to get more results from measurements on our STADIVARI.
STOE: What are your plans for the future for the instrument?
TW: Firstly, we have to conduct some battery measurements for the project report for the STADIVARI + Nordseekammer project and then we will be looking into different kinds of materials which are expected to show similar effects to SrTiO3.
In the long run, we are considering the options of upgrading the Nordseekammer or even construct another chamber which offers different experimental setups. We would for example be curious to add a magnet or a pressure chamber to the setup. Another type of experiment which we are very curious about is in-situ layer deposition or growth. Therefore, we could envision a chamber which can do pulsed layer deposition, flash lamp annealing as our colleagues use it to produce battery components or other methods for layer growth.
 J. Hanzig, M. Zschornak, F. Hanzig, et al., Phys. Rev. B (2013), 88, 024104.
 C. Richter, M. Zschornak, D. Novikov, et al., Nat Commun (2018), 9, 178.
 J. Hanzig, E. Mehner, S. Jachalke, et al., New Journal of Physics (2015), 17, 023036.
 M. Nentwich, T. Weigel, C. Richter, et al. J. Synchrotron Rad. (2021), 28, 158.