2025 Program
Event: Dorothee Schaffner (University of Würzburg) and Prof. Naomi Ginsberg (University of California, Berkeley)
When: December 12th, 2025
12-1 PM EST
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Early Career Talk: “Auger electron spectroscopy of the astrochemical molecule HNCS”
Dorothee Schaffner (University of Würzburg)
Biography: Dorothee Schaffner studied chemistry at the University of Würzburg from 2017 to 2022. She then joined the group of Prof. Dr. Ingo Fischer for her PhD thesis, supported by a Kekulé doctoral scholarship. Here, she primarily investigates reactive molecules of astrochemical relevance in the gas phase with VUV or soft X-ray radiation. She employs (time-resolved) X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, Auger electron spectroscopy and threshold photoelectron spectroscopy and carries out her measurements at various storage rings and free-electron lasers across Europe.
Abstract: Isothiocyanic acid is the simplest isothiocyanate and has been detected in space toward different interstellar objects. Investigating the interaction of HNCS with X-ray radiation is critical to understanding its fate in the presence of high energy photons in space.
In this talk I will give a short overview of inner-shell spectroscopy and focus on our recent experimental investigations of HNCS by Auger electron spectroscopy in the gas phase. The spectra are compared to simulations and spectra of related molecules. This intends to give insights into the observed transitions and the influence of heavy atom substitution on Auger electron spectra. Furthermore, the fragmentation of HNCS after core ionization is studied by Auger electron/photoion coincidence spectroscopy.
Talk: “Harnessing energy scales and microscopic fluctuations to manipulate bottom-up assembly of nanomaterials”
Prof. Naomi S. Ginsberg (University of California, Berkeley)
Biography: Naomi S. Ginsberg is a Professor of Chemistry and Physics at University of California, Berkeley and a Faculty Scientist in the Materials Sciences and Molecular Biophysics and Integrated Imaging Divisions at Lawrence Berkeley National Laboratory, where she has been since 2010. She currently focuses on elucidating electronic and molecular dynamics in a wide variety of soft electronic and biological materials by devising new electron, X-ray, and optical imaging modalities to characterize dynamic processes at the nanoscale, as a function of their heterogeneities and over a wide range of time scales. Naomi received a B.A.Sc. degree in Engineering Science from University of Toronto in 2000 and a Ph.D. in Physics from Harvard University in 2007, after which she held a Glenn T. Seaborg Postdoctoral Fellowship at Lawrence Berkeley National Lab. Her background in chemistry, physics, and engineering has previously led her to observe initiating events of photosynthesis that take place in a millionth billionth of a second and to slow, stop, and store light pulses in some of the coldest atom clouds on Earth. She is the Berkeley lead of STROBE, a multi-university NSF Science and Technology Center devoted to imaging science, a member of the Kavli Energy Nanoscience Institute at Berkeley, and the recipient of a David and Lucile Packard Fellowship in Science and Engineering (2011), a DARPA Young Faculty Award (2012), an Alfred P. Sloan Foundation Fellowship (2015), and a Camille Dreyfus Teacher-Scholar Award (2016) in addition to a series of teaching awards in the physical sciences and the campus-wide Carol D. Soc Distinguished Graduate Student Mentoring Award (2022). In 2017-18 she was a Miller Professor for Basic Research in Science at UC Berkeley and was designated a Kavli Fellow. In 2019 she was the Kroto Lecturer in Chemical Physics at Florida State University, and she was an APS Laser Science Visionary Speaker in 2024. She is the recipient of the 2020 ACS Early-Career Award in Experimental Physical Chemistry and became a Fellow of the American Physical Society in 2021.
Abstract: By taking advantage of adjustable short-range attractive interactions of electrostatically stabilized colloidal nanocrystals, we demonstrate an unusual degree of control over the phase behavior of a nanoscale system, studied via in situ small angle X-ray scattering (SAXS). This control is exemplified through the use of a metastable liquid intermediate state that enables varying the colloidal crystallization rate by over three orders of magnitude, along with predictive control of crystal yield, size, and crystallinity. Most strikingly, we reveal that crystallinity can be increased with increasing driving force.1
While these investigations rely on in situ small angle X-ray scattering, we employed the additional power of coherence in X-ray photon correlation spectroscopy (XPCS) to characterize the microscopic dynamics of the colloidal nanocrystals both in colloidal suspension and in the intermediate state. By going beyond snapshots of structure to snapshots of dynamics we uncover richly varied ~microsecond dynamics as a function of location in the phase diagram, illustrating the ability to nucleate superlattices from condensed intermediate states progressively further from equilibrium and further from Fickian fluctuations.
With this non-equilibrium inspiration, we also show how light absorption and the associated photochemistry systematically alters the system phase behavior. Ultimately, the multiscale characterization of and manipulation of electrostatically stabilized nanocrystals paves the way to more clearly explain the design rules for nanoscale interaction potentials so that nanomaterial assemblies can achieve more effective functionalities via deterministic and predictive control.
[1] Tanner, C. P. N. et al. Enhancing nanoscale charged colloid crystallization near a metastable liquid binodal. Nat. Phys. 1–9 (2025) doi:10.1038/s41567-025-02996-5.
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