We are offering following positions:

2 PhD positions

The RTG DynCAM program comprises a series of complementary experimental and theoretical projects, investigating and controlling the electron and nuclear dynamics down to the quantum level. In the focus are advanced techniques for the preparation of controlled atomic, molecular and cluster ensembles, combined with modern ultra-short laser techniques, as well as a variety of theory approaches. Collaborations with UBC offer an international environment with opportunities for extended research stays in Vancouver, Canada.

We are looking for highly motivated, enthusiastic, and team-oriented candidates that are eager to learn new methods, are passionate about science, and hold a master’s degree or equivalent in physics, chemistry, or related areas.

Please send your application as a single pdf-file including a letter of motivation, a CV, certificates of your university degree (including grades), a transcript of records and contact details of two references to our coordinator Simone Ortolf: info@rtg-dyncam.de

Further information:

The duration of contracts within the RTG is 36 months and the salary corresponds to TV-L E13 (75%). The University of Freiburg seeks to increase the number of female scientific faculty members and therefore strongly encourages qualified women to apply for the position. The university committed to provide a family-friendly workplace. In case of equal qualification, persons with disabilities will be given preference.

PhD position

The research group of Prof. Tobias LAU is looking for a phD student who is interested in the project:

X-ray magnetic circular dichroism of state-controlled transition elements

About the project:

Ion mobility mass spectrometry or electronic state chromatography, combined with gas-discharge ion sources, is an ideal tool to select ions of 3d transition elements in ground or excited electronic states that are not necessarily linked by dipole-allowed or one-electron transitions. Here, ion mobility mass spectrometry and cryogenic ion trapping with our ion trap endstation at BESSY II will be employed to prepare cold and electronic state-selected ions of 3d transition elements for x-ray spectroscopy. Ionization of transition elements in a gas discharge produces ground and excited state electronic configurations that are separated by the mobility analyser. A cryogenic ion trap will be used to accumulate and cool the ions, and serves as the interaction region with X-ray photons. For a given element, ground states, as well as long-lived excited states that differ in 3d electron configuration, will be of particular interest for high-resolution X-ray absorption and X-ray linear dichroism spectra in order to fundamentally test XMCD sum rules, and will give a library of experimental XAS and XMCD data that are important for computational developments in high-level theory for X-ray absorption spectroscopy. Changes in transition metal L-edge excitation energy with 3d electron configuration will also contribute to a fundamental understanding of the empiric concept of oxidation states. First steps towards state or isomer-selective X-ray spectroscopy of larger ions will be made. The work program will consist of an initial phase of laboratory work to prepare transitions metal ions in well-defined electronic states, followed by campaigns at the BESSY II synchrotron radiation facility for X-ray absorption and XMCD spectroscopy.

(T. Lau, B. von Issendorff)

PhD position at Helmholtz Center Berlin – Prof. Tobias Lau

Electronic structure of isolated transition metal complexes in unusually high oxidation states and their relation to the oxygen evolving complex (T. Lau)

We are investigating the electronic and magnetic properties of transition metal ions and transition metal centers in clusters, organometallic coordination entities, and chelate complexes that we build up and investigate atom by atom or ligand by ligand. To this end, we operate a unique cryogenic ion trap setup for gas-phase soft-x-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectroscopy as well as a liquid-jet setup for resonant inelastic x-ray scattering (RIXS) at BESSY II, both of which are designed to study highly-dilute gas-phase and liquid-phase matter with highest sensitivity. We use these tools to arrive at a fundamental understanding of energy levels, spin states, oxidation states, and valence electron delocalization in coordination entities of 3d, 4d, 5d, and 4f transition elements.
Here, we specifically investigate the electronic structure of isolated transition metal complexes in unusually high oxidation states and their relation to the oxygen evolving complex. The main objective is to prepare coordination entities with highly oxidized metal centers in the gas-phase, and to elucidate their electronic structure via x-ray spectroscopy, thus determining their spin state and probing the degree of metal-ligand orbital hybridization. The species of interest are prepared from magnetron sputtering, gas-phase ion chemistry, and electrospray ionization. Mass-selected samples are probed in a cryogenic ion trap. The candidate will work closely with a team of postdoctoral research associates and PhD students as well as in cooperation with renowned labs.

We are seeking for a highly motivated candidate with a strong interest in new methods of experimental x-ray spectroscopy of gas-phase atomic, molecular, and cluster ions. To qualify for this position, the candidates should hold or have

  • a recent M.Sc. degree in inorganic chemistry, physical chemistry, physics, or a related field
  • experience with experimental work in one or more of the following areas: spectroscopy, mass spectrometry, transition metal complexes, high vacuum, cryogenics, ion traps
  • ideally have gained experience with x-ray absorption spectroscopy, x-ray magnetic circular dichroism spectroscopy, or resonant inelastic x-ray scattering at synchrotron radiation sources or free-electron lasers
  • the ability and willingness to perform cutting-edge research in international teams and to participate in beam times, which also includes occasional night or weekend working hours