Using three ALS beamlines, researchers have determined the structure of AgBIS, a three-domain plant sesquiterpene synthase that is a biosynthetic precursor to an advanced biofuel with physico-chemical properties similar to D2 diesel.

An international research team working at ALS Beamline 11.3.1 studied metal-ion-mediated reactions of 2-pyridinealdoxime (the simplest 2-pyridyl oxime and the only aldoxime in this family) and observed novel transformations of the ligand.

Researchers at the University of California, Berkeley and the ALS have used the far/mid-infrared FTIR of ALS Beamline 1.4 to study the plasmon excitation in graphene. They observed remarkably strong and tunable plasmon excitations in the Terahertz range, which demonstrate the exotic behaviour of 2D massless Dirac electrons and shed new light on graphene's application in THz metamaterials.

Researchers at the University of Oregon and the ALS have used the high coherence and brightness of the ALS to examine the amount of microscopic memory in a magnetic system as a function of both length scale and applied field.

Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures.

Researchers report the most direct experimental verification of Mott-Hubbard and charge-transfer insulators using x-ray emission spectroscopy in transition-metal (TM) fluorides at Beamline 8.0.1.1.

How plants refill the vessels that transport water has been under debate for the last 30 years owing to the lack of an in vivo visualization tool at the appropriate temporal and spatial resolution. Now, data generated using high-resolution x-ray computed tomography (HRCT) on Beamline 8.3.2 provide the first visualization of the mechanism plants use to refill vessels, and show water droplets being pumped into air-filled vessels from the surrounding plant tissue, forcing the air bubbles back into solution.

While most materials melt when they are heated, some materials do exactly the opposite – they melt upon cooling. While a few exotic materials systems were known to exhibit the phenomenon of “retrograde melting,” it was only recently that this effect was observed in the most common semiconductor material used for semiconductors and solar cells – Silicon.

The Warm Dense Matter regime falls in between condensed matter and plasma, where it is defined by temperatures of ~ 10⁴-10⁵ K (~ 1-10 eV) and near solid densities. Studying this superheated solid or strongly coupled plasma can provide key understandings about non-equilibrium phase transitions and energy relaxation processes, related to phenomena found in astrophysics, inertial confinement fusion, as well as applied processes such as laser machining and ablation.

Scientists from DOE’s National Energy Technology Laboratory (NETL) and Berkeley Lab used scanning tunneling microscopy (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamline 9.3.2 to examine nanocrystals and continuous thin films of α-Fe₂O₃ grown on Au(111), and to gain insight into the structure-property relation of a material under realistic conditions.

Scientists from Carnegie Institution of Washington and Berkeley Lab used the scanning transmission x-ray microscope on ALS Beamline 5.3.2 to detect remnants of protein and chitin in the exoskeleton of a 417-million-year-old fossil of an extinct mega-scorpion, a discovery that reveals organic material in fossils several hundred million years older than previously found chitin-containing fossils.

Using the polarimeter capabilities of our x-ray spectrometer, we have recently measured the polarization of x-ray photons emitted in a molecular core-to-core transition accompanying resonant inelastic x-ray scattering (RIXS). In this study, we have measured KL emission spectra corresponding to the filling of a 1s core hole by a 2p core electron following core-hole excitation Cl(1s)^-1→(11a₁)¹ in CF₃Cl, and Cl(1s)^-1→(6σ)¹ in HCl (hν=2823,5 eV in both cases). We have observed a linear dichroism in polarized x-ray-emission spectra. In a combined experimental and theoretical effort, we showed this effect is sensitive to coupling between the molecular field (MF) and spin-orbit interactions and interpreted the observed dichroism in terms of population differences in the 2p_x;y;z inner-shell orbitals. Polarized RIXS offers a unique opportunity to determine spin-orbit-component populations, providing a new probe of MF effects on electronic structure.