Garlef Wartner

Garlef during his 1st beamtime with the SOL³ setup.

1.6.2018 Welcome Garlef Wartner!

PhD candidate Garlef Wartner from Stade, Lower Saxony, joined our team. A very warm welcome!


The night-shift team, which finally got a photoelectron spectrum of liquid ammonia: (from left to right) Bernd, Pavel, Steve, Phil, Ryan, Robert, Tillmann, and Dennis.

2.5.2018 First liquid ammonia spectra taken with our SOL³ setup

After many attempts at FHI and at BESSY we finally got a stable liquid ammonia jet running in our SOL³ setup under vacuum conditions. Phil and Tillmann managed to enhance the duration of the running jet to almost 8 hours – enough time to measure the valence band, core levels, angular photoelectron dependencies, salts dissolved in liquid ammonia at good statistics, and ultimatively, high-concentrated solvated electrons from dissolved Lithium metal in liquid ammonia. Please watch this video on Youtube and share the moment where we collected our first liquid ammonia photoelectron spectrum. 



Dennis on his first day – standing in front of the shiny hemispherical analyzer.

1.5.2018 Welcome Dennis Hein!

PhD candidate Dennis Hein from Aalen, Baden-Württemberg, joined our team. A very warm welcome!


Our TOC graphic highlights the various species present at the hematite nanoparticle – aqueous solution interface.

30.4.2018 Our article about the water dissociation at the surface of hematite nanoparticles has been published in Chemical Science

Together with our colleagues from FHI we investigated the hematite nanoparticle – water interface by (resonant) liquidjet photoelectron spectroscopy. This method is sufficiently sensitive for the detection of adsorbed hydroxyl species, resulting from the water dissociation at the nanoparticle surface in aqueous solution. For more information click here


Two liquid-jets hit each other and form a flat leaf-shaped water surface. The hole behind the flat-jet is the 500-µm small orifice of our R4000 electron analyzer.

26.4.2018 First photoelectron spectra from a flat-jet

Bernd Winter and his team from FHI tested for the first time their new flat-jet assembly in our SOL³ setup under vacuum conditions. When two (identical) liquid-jets hit under a certain angle with the same flow a flat leaf-shaped liquid surface will form, which thickness can be adjusted to less than a micrometer. Bernds team also managed to get the first photoelectron spectra of liquid water from a flat-jet. Well done!

SOL³ at magic angle

It looks like it is falling to the side, but the suspension holds our R4000 at the magic-angle.

17.3.2018 Rotating the machine to magic angle

Over the weekend we needed to rotate our electron analyzer to 54.7° relative to the polarization axis of the synchrotron light at the U49/2-PGM-1 beamline of BESSY. At this so-called magic angle we can determine relative intensities from different solute species in aqueous solution from a liquid jet, which are then only depending on probing depth and ionization cross section, ignoring complex photoelectron angular distribution functions. We used this geometry of our electron analyzer to determine the depth-depending dissociation constant of HSO4-/SO42- in water as a function of concentration and kinetic energy. Rotating the machine only takes 10 minutes using a pulley assembly. All seven turbomolecular pumps of the HIPP-2 R4000 electron analyzer are off during the rotation, but the roughing pumps are still running, allowing for a fast run-up of the experiments compared to a complete venting.

Stephan Thürmer, Robert Seidel at the SOL³PES

Like in the good old times - Stephan and Robert taking measurements at BESSY.

14.3.2018 Dr. Stephan Thürmer from The University of Kyoto visited us

During his Europe-tour, Stephan Thürmer, very welcomed long-term expat and designer of the previous liquidjet experimental setup, the LiquidjetPES at BESSY, joined us for one day in our commissioning beamtime. As in the good-old times, Stephan got immediately familiar with our new SOL³ system and gave valuable input to improve the lens tables of our hemispherical electron analyzer, pushing the electron transmission to new highs.

Dr. Alex Gaiduk from UChi

We are very happy to having Alex at BESSY, even the glove box...

13.12.2017 Dr. Alex Gaiduk from The University of Chicago visited us

Our theory collaborator from Giulia Gallis group at ‘UChi’, Alex Gaiduk, visited our group and took a look at our experimental setups at BESSY. He was impressed by the machines that confirm (and on rare occasions ‘readjust’) his invaluable calculated energies and redox potentials from aqueous salt solutions. He also presented his newest ab-initio calculations on one of the hot topics in the water-community: the precise energy position of liquid water’s conduction band - an important number that is experimentally very hard to derive. For more details on Alex work check out his newest article and the Galli group webpage.

Iron-oxo oligomers in aqueous solution

Our back cover in PCCP issue 48, 2017.

13.11.2017 Our article about the iron-(III)-oxo oligomer formation in aqueous solution is online

Together with the research groups of Franziska Emmerling at the BAM Federal Institute for Materials Research and Testing, Berlin, Ralph Krähnert at the Technical University Berlin, and  Bernd Winter at Fritz-Haber-Institut der Max-Planck-Gesellschaft, we looked into the formation process of small iron-oxo oligomers in aqueous solution. This chemical process is crucial for the formation of nanoparticles in aqueous phase. By a combination of Raman spectroscopy, Small Angle X-ray scattering and Liquid-microjet resonant photoelectron spectroscopy we could identify and measure the electronic structure properties of the iron-oxo oligomeric seeds that were produced by adding sodium hydroxide to our iron chloride solution. Our findings have been published in Physical Chemistry Chemical Physics. For more details click here.

Gas-dynamical virtual nozzle, Sol³PES

Claudia, Bernd, and Sebastian are discussing the newest data from the gas-dynamic virtual nozzle experiments.

28.9.2017 First gas dynamic virtual nozzle measurements with our setup

Together with our collaborators from FHI Berlin and IOM Leipzig we successfully measured for the first time at our setup a liquid jet, surrounded by a strong gas-stream to investigate gas-liquid interactions. Claudia, Bernd, and Sebastian from FHI were interested in the CO2 uptake of monoethanolamine in aqueous solutions and looked for its reaction products with respect to the gas-solution interface, and as a function of pH. An exciting experiment!

SOL3PES setup

Our new SOL³PES setup goes into user operation.

31.7.2017 Our new SOL³PES setup goes into user operation

Just in time for the start of the user operation of our new SOL³PES setup we got a technical article accepted in Review of Scientific Instruments, describing in detail its capabilities and features. Click here.

Emmy-Noether meeting 2017

Group picture of the 2017 Emmy-Noether stipend holders and alumni (Credit: DFG / David Ausserhofer)

19.7.2017 Emmy-Noether meeting in Potsdam

Robert joined the annual three-day meeting as Emmy-Noether-‘freshman’, which took place for the 16th times. This year the current Emmy-Noether stipend holders and alumni met at the lovely Templiner See in Potsdam to talk about funding opportunities, career options after the Emmy-Noether stipend and the changes to the general social conditions in science and politics. For more details check out this DFG site (in German only).

Arno Bergmann at BESSY II

 Arno is preparing nanoparticles in the glove box.            

10.4.2017 Beamtime at the U49/2-PGM-1 beamline at BESSY II

This beamtime we further explored metal oxide nanoparticles in water by liquidjet photoelectron spectroscopy. Arno prepared an Fe3O4 nanoparticle solution in our glove box – it is not an easy experiment. Jet stability and concentration are at their limits (and beyond…).

Beamtime at UE52-SGM-1 beamline at BESSY II

Setting up the SOL³PES station at the UE52-SGM-1 beamline.

20.3.2017 Beamtime at UE52-SGM-1 beamline at BESSY II

We measured for the first time with our new SOL³PES setup angle-resolved valence photoelectron spectra of neat water. These measurements are key to derive the so-called anisotropy parameter of the outer water valence orbitals. By comparison with gas phase water anisotropy parameter values we can directly determine elastic and inelastic scattering behavior of the outgoing photoelectrons and indirectly the electron mean free path in water – a very important measure for the probing depth. To get our machine to the UE52-SGM-1 beamline we had to use the BESSY crane.

This beamtime was part of the 1st international photonschool at HZB, where 20 international postdocs, master and Phd students got hands-on experience on several experimental BESSY stations, including our SOL³ setup. See more

HZB/M. Setzpfandt

The lithium chloride solution to be investigated was injected as an extremely fine stream of liquid into a vacuum chamber and analysed with soft X-ray emissions. Credit: HZB/Setzpfandt

9.3.2017 Sensitive Method for Detecting Ion Pairs in Aqueous Solutions

Our work on Electron-Transfer Mediated Decay in aqueous solutions was published in Nature Chemistry. See more

1.3.2017 Welcome Arno Bergmann!

Dr. Arno Bergmann, from TU Berlin, joins the team as a postdoctoral research fellow. A very warm welcome!

1.1.2017 Our new group started!