Siegfried Glenzer

Oct 3, 2024 | nature.com | Guillaume Morard |Jean-Alexis Hernandez |Dimosthenis Sokaras |Hae Ja Lee |Eric Galtier |Siegfried Glenzer | +10 more

AbstractMolten silicates at depth are crucial for planetary evolution, yet their local structure and physical properties under extreme conditions remain elusive due to experimental challenges. In this study, we utilize in situ X-ray diffraction (XRD) at the Matter in Extreme Conditions (MEC) end-station of the Linear Coherent Linac Source (LCLS) at SLAC National Accelerator Laboratory to investigate liquid silicates.

Jul 27, 2024 | nature.com | Siegfried Glenzer

AbstractWe report time resolved observations of the crystallization from liquid hydrogen, supercooled to temperatures below the melting point, using 11.2 keV X-ray diffraction from the Linac Coherent Light Source (LCLS). Changes to the metastable solid and liquid structure factors have been dynamically measured. This allows for a direct determination of the lowest energy crystal polymorphs, the stacking probabilities, as well as the liquid and solid densities and temperatures.

Nov 21, 2023 | link.aps.org | Andreas Hermann |Siegfried Glenzer |Mungo Frost

Raman spectra from molecular systems are typically regarded as comprising a set of sharp peaks. These arise from both single-molecule modes and extended Γ point phonons being, in theory, harmonic oscillators. Broadening is typically assigned to thermal, linewidth, and anharmonic effects. Here we measure significant broadening in the Raman signal from partially deuterated water ices VII and VIII, which is absent in the pure systems.