Christian Zaubitzer


Last Name

Zaubitzer

First Name

Christian

ORCID

0000-0003-3876-2476

Organisational unit

02891 - ScopeM / ScopeM

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2019 - 201922020 - 20255
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Publications 1 - 7 of 7
  • 3D-structured supports create complete data sets for electron crystallography
    Item type: Journal Article
    Wennmacher, Julian T.C.; Zaubitzer, Christian; Li, Teng; et al. (2019)
    Nature Communications
    3D electron crystallography has recently attracted much attention due to its complementarity to X-ray crystallography in determining the structure of compounds from submicrometre sized crystals. A big obstacle lies in obtaining complete data, required for accurate structure determination. Many crystals have a preferred orientation on conventional, flat sample supports. This systematically shades some part of the sample and prevents the collection of complete data, even when several data sets are combined. We introduce two types of three-dimensional sample supports that enable the collection of complete data sets. In the first approach the carbon layer forms coils on the sample support. The second approach is based on chaotic nylon fibres. Both types of grids disrupt the preferred orientation as we demonstrate with a well suited crystal type of MFI-type zeolites. The easy-to-obtain three-dimensional sample supports have different features, ensuring a broad spectrum of applications for these 3D support grids.
  • Heterogeneity of nano-sized zeolite crystals
    Item type: Journal Article
    Wennmacher, Julian T.C.; Li, Teng; Zaubitzer, Christian; et al. (2020)
    Microporous and Mesoporous Materials
    Analytical characterization and evaluation of performance of zeolite catalysts are normally done under the assumption of a homogeneous batch. However, it is known that in the same batch particles of the zeolite ZSM-5 can be very different one from another, regarding their aluminum content and catalytic performance. Here, we quantify the extent of this heterogeneity within a singular synthesis batch of nanocrystalline ZSM-5, through the analysis of single crystalline individua. We found that the overall aluminum content was distributed unequally between two kinds of crystal populations. Cornered crystals contained three times more aluminum than round-shaped crystals. This observation connects morphological differences to the chemical composition of each zeolite crystal for the first time. This finding could provide a means for performance optimization in zeolite synthesis.
  • Diffusion anisotropy of Ti in zircon and implications for Ti-in-zircon thermometry
    Item type: Journal Article
    Bloch, Elias M.; Jollands, Michael C.; Tollan, Peter; et al. (2022)
    Earth and Planetary Science Letters
    Ti-in-zircon thermometry has become a widely used tool to determine zircon crystallization temperatures, in part due to reports of extremely sluggish Ti diffusion perpendicular to the crystallographic c-axis in this mineral. We have conducted Ti-in-zircon diffusion experiments, focusing on diffusion parallel to the c-axis, at 1 atm pressure between 1100 and 1540 °C, with oxygen fugacities equivalent to air and the Ni-NiO buffer. There is no resolvable dependence of Ti diffusion in zircon upon silica or zirconia activity, or upon oxygen fugacity. The diffusion coefficient of Ti in zircon is found to be a weak function of its own concentration, spanning less than 0.5 log units across any profile induced below 1300 °C. Ti diffusion in zircon, parallel to the c-axis at 1 atm pressure, is well described using: [Formula presented] where R is the gas constant in J/(mol⋅K). In conjunction with diffusion coefficients for Ti in zircon perpendicular to the c-axis reported by Cherniak and Watson (2007), strong diffusion anisotropy for Ti in zircon is observed. Diffusion parallel to the c-axis is ∼4-5 orders of magnitude faster than diffusion perpendicular to the c-axis within the experimentally constrained temperature range shared between these two studies (1540-1350 °C). This difference increases if the data are extrapolated to lower temperatures and reaches ∼7.5-11 orders of magnitude between 950-600 °C, a typical range for zircon crystallization. Diffusion of Ti in natural zircons will predominantly occur parallel to the c-axis, and the Ti-in-zircon thermometer appears susceptible to diffusive modification under some crustal conditions. Temperatures calculated using this system should therefore be evaluated on a case-by-case basis, particularly when considering high-T, slowly cooled, reheated and/or small zircons.
  • Operando Scanning SAXS/WAXS Cell Design for Multiscale Analysis of All-Solid-State Battery Systems
    Item type: Journal Article
    von Mentlen, Jean-Marc; Fiedler, Magdalena; Wood, Vanessa; et al. (2025)
    Batteries & Supercaps
    Operando X-ray scattering techniques, particularly small- and wide-angle X-ray scattering (SAXS/WAXS), have been key for elucidating the physicochemical processes governing liquid-electrolyte batteries by providing real-time insights into phase transformations and nanoscale structural evolution. However, extending these methods to all-solid-state batteries has been experimentally challenging due to high X-ray absorption and nonideal operating pressures in transmission mode. Here a novel operando electrochemical cell design is presented that enables cross-sectional scanning SAXS/WAXS measurements, while maintaining the pressure necessary for solid-state operation. Applying this scanning SAXS/WAXS technique to all-solid-state lithium-sulfur batteries, it enables simultaneous mapping of the crystalline phase evolution and the nanoscale structural changes across distinct cell components during cycling. Spatially resolved WAXS revealed significant heterogeneity in the formation and distribution of Li₂S within the composite cathode. Simultaneously, WAXS captured an anisotropic lithiation mechanism in the Li-In anode, evidenced by the preferential disruption of In(110) planes and suggesting amorphous LiIn formation. Combined analysis of stable SAXS profiles and WAXS-derived Li₂S nanocrystallite sizes suggest that the sulfur conversion occurs within the nanopores of the templated carbon host. Control experiments using a liquid-electrolyte Li-S system validated the technique’s sensitivity to detect expected nanoscale changes, confirming the genuineness of the solid-state observations.
  • Design guidelines for an electron diffractometer for structural chemistry and structural biology
    Item type: Journal Article
    Heidler, Jonas; Pantelic, Radosav; Wennmacher, Julian T.C.; et al. (2019)
    Acta Crystallographica Section D: Structural Biology
    3D electron diffraction has reached a stage where the structures of chemical compounds can be solved productively. Instrumentation is lagging behind this development, and to date dedicated electron diffractometers for data collection based on the rotation method do not exist. Current studies use transmission electron microscopes as a workaround. These are optimized for imaging, which is not optimal for diffraction studies. The beam intensity is very high, it is difficult to create parallel beam illumination and the detectors used for imaging are of only limited use for diffraction studies. In this work, the combination of an EIGER hybrid pixel detector with a transmission electron microscope to construct a productive electron diffractometer is described. The construction not only refers to the combination of hardware but also to the calibration of the system, so that it provides rapid access to the experimental parameters that are necessary for processing diffraction data. Until fully integrated electron diffractometers become available, this describes a setup for productive and efficient operation in chemical crystallography.
Publications 1 - 7 of 7