© Karen Appel/XFEL
The first lecture of the DeepDyn seminar in the winter semester 2024/2025 will be given by Karen Appel. Karen is a scientist at the European XFEL (X-Ray Free-Electron Laser Facility) in Schenefeld and Hamburg, a joint X-ray laser research facility involving 12 European countries.
In her lecture "Accessing electronic and structural properties of major Fe-bearing geomaterials at conditions close to the core-mantle boundary: an experimental approach" she will present her experiments with ferrous geomaterials under high pressure and high temperatures.
Early Career Co-Host this time is Maximilian Schulze.
The DeepDyn seminar takes place online as a zoom-meeting. DeepDyn members will automatically receive the access link before the seminar. We ask external seminar guests to register for the seminar in order to receive the access link.
Accessing electronic and structural properties of major Fe-bearing geomaterials at conditions close to the core-mantle boundary: an experimental approach
© Karen Appel
Abstract
The structural and electronic behavior of Fe-bearing geomaterials may add important information on the formation process and the evolution of the Earth’s core. FeO as the endmember of the solid solution line (Fe,Mg)O is a model material that may exist at the core mantle boundary and may have been formed by exsolution from an Fe-rich melt at an early stage of core formation. FeO is known to show different spin states and structures with pressure which have a major effect on the properties of the lower mantle-core boundary.
Atomic and recently also electronic structures of FeO and (Fe,Mg)O have been repeatedly studied with shock compression and static high-pressure techniques. High pressure-high temperature experimental data is still scarce at conditions of the core-mantle boundary. In our DeepDyn sub-project, we apply dynamic compression using an optical long pulse laser to create short lived extreme states of matter. The sample is exposed to a short flash of X-ray light from a Free-electron laser to obtain information on electronic and atomic structure by X-ray emission spectroscopy and X-ray diffraction at peak pressures and temperatures, respectively. In addition, typical shock diagnostics are applied to obtain information on temporal evolution of pressure and temperature during shocks.
In this presentation, after an introduction to the scientific topic, I will give an overview of the experimental methods and describe results from a first beamtime in August on (Mg,Fe)O along with results on FeO from an earlier campaign.
Next edition of DeepDyn seminar
with Ebru Bozdağ