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Open Positions

a PhD-Student (f/m), in the field of Physics, Chemistry of Materials Science

a Postdoctoral Scientist (f/m), in the field of Physics, Chemistry or Materials Science

PhD position (Doktorand) for investigating the charge transfer processes in 3d-transition metal complexes in solution using soft X-ray spectroscopies from a liquid microjet

Wiss. Mitarbeiterin / Wiss. Mitarbeiter

3/4-part-time job limited to 3 years

Entgeltgruppe 13 TV-L FU


Soft X-ray spectroscopies are powerful tools for probing the local electronic structure of matter. Its application to highly volatile liquid phase has been experimentally hampered though until recently. In introducing the liquid microjet technique to X-ray synchrotron light sources our group has pioneered various aspects of the electronic-structure interaction in liquid solution, mostly aqueous solutions, as well as neat liquid water. We operate different experimental stations at BESSY II synchrotron facility (Berlin, Germany) which enables the detection of either photons or electrons (using X-ray absorption, X-ray emission, resonant X-ray scattering, and direct as well as resonant photoelectron spectroscopies) to study both the ground and excited states of liquid solutions. Given the complementary information these two schemes provide we can accurately interpret the respective X-ray spectra. In addition interpretation of experimental results is assisted by high-level quantum mechanical calculations. We are thus equipped to explore the electronic-structure interactions occurring in liquid solution on the molecular level which includes ultrafast energy and charge transfer between solute and solvent, and our experiments can be also tuned to interfacial versus bulk solution sensitivity. The latter allows for an accurate investigation of interfacial solvation phenomena. The molecular systems studied by our group span a wide range, from small atomic ions (especially transition metals) to larger molecules and molecular complexes (e.g., metal porphyrins) relevant for catalysis- and energy-driven research, as well as relevant for the larger field of radiation chemistry.

Condition of employment:

    Master or Diplom in Physics or Chemistry

Desirable:
    Strong background in SOME of the following fields
•    experiences of taking soft X-ray spectroscopy (XAS, XES,XPS) at synchrotron facility
•    proficient in symmetry selection rule (the knowledge of group theory is desired)
•    experiences of handling liquid micro-jet, and/or liquid flow-cell
•    experiences of theoretical calculations (DFT, ab initio, semi-empirical, ect.)
•    experiences of measuring UPS, UV-Vis, IR are appreciated

Applications, quoting the reference code X-ray spectroscopy shall be addressed no later than July 21st, 2014 to Dr. Jie Xiao (Email: jie.xiao@helmholtz-berlin.de)

Bachelor, PhD, PostDoc and Staff scholarships available

Through the EU-METALIC II partnership, candidates from Lot countries Morocco, Egypt, Tunisia, Algeria and Libya and through EMINTE candidates from India can apply for scholarships and encouraged to study in our group. For details, please refer to www.eu-metalic2.eu and http://eminte.eu/. The application deadline for EU-METALIC II is January 17th, 2014 and December 1st 2013 for EMINTE. Do not hesitate to contact erasmus-mundus@fu-berlin.de and emad.aziz@helmholtz-berlin.de if you are interested.

Helmholtz Call for 2014 CSC Fellowship Applicants (PhD and PostDoc)

Through the Chinese Scholarship Council, candidates from China can apply for scholarships and encouraged to study in our group. PhD positions up to 4 years, sandwich PhD positions up to 24 months and PostDoc positions up to 12 months are supported. For details, please refer to http://en.csc.edu.cn/ . Do not hesitate to contact emad.aziz@helmholtz-berlin.de if you are interested.

Ultrafast Dynamics Lab (PhD students, Master students and diploma students)

Research profile:

Our research is focused on studying the structure and dynamics of biochemical systems in solutions. Currently we are using the Bessy II synchrotron as an x-ray light source giving us access to X-ray pulses in an energy range from 100 to 1500 eV. This energy range covers the K-edge of life elements (oxygen, nitrogen, carbon …) as well as the L-edge of transition metals (first row 3d- elements). We have developed spectrometers allowing us to investigate these elements under physiological conditions (room or body temperature and pressure). Note that soft x-rays require ultra high vacuum and it is not trivial to introduce systems under ambient conditions to be investigated there.

Our previous success allowed us to win an ERC-starter grant for investigating ultra-fast dynamics in solution and at interfaces for chemical and biological applications. This will allow us to proceed on the following two pillar approach for pump and probe measurements:

  1. Using a laser pump- and a X-ray probe-pulse from the synchrotron, measuring either x-ray transmission or fluorescence. Synchrotron radiation will enable a high intensity probe, but limits the time resolution to 50 ps.
  2. Using a laser pump- and high-harmonic X-ray probe-pulse, using primarily photoelectron spectroscopy with the possibility to extend the technique to X-ray transmission and fluorescence measurements. The X-ray pulse based on high harmonic generation will be limited in intensity but allows a femto-second time resolution.

 

Desired qualification:

  • Experience with high-harmonic generation
  • Experience with X-ray spectroscopy, synchrotron radiation, and vacuum systems

 

 

For our new research efforts into time resolved spectroscopy as well as synchrotron based x-ray spectroscopy usually several opportunities for a Master or Bachelor thesis exist.

Also PhD positions become periodically available for current possibilities contact:

emad.aziz@helmholtz-berlin.de

 

A new PhD position is available as of May 2013 at the Ultrafast Dynamics Lab:

Ultra-Fast Dynamics in Solutions and at Interfaces

 

The research addresses a wide range of processes occurring under interaction of laser radiation with biochemical molecular systems in solutions. Among these are charge transfer, modification of the geometric and bond structure, electron emission in a strong laser field, and coherent excitation of electronic wave packets in complex systems. A pump-probe laser scheme will be used to investigate dynamics of these processes. Experiments will be conducted with the use of laser sources (Ti: sapphire laser, optical parametric amplifier, high-order harmonic generation setup) available at the newly built laser lab at the Freie Universität Berlin.

Vacancy: Student assistant

We are looking for our Young Investigator Group for Functional Materials in Solution (F-NFF) at Helmholtz Zentrum Berlin Adlershof for a student of Physics/Chemistry/Mathematics or Computer Science with a perfect command of German and English language in speech and writing for designing our website. You should be able to translate in an excellent way scientific texts.

The position is available and is limited for three months with about 106 working hours.

Preferably:

  • Experience with the layout and design of websites
  • Three to four completed semesters
  • Initiative
  • Organizational talent

For any further question please contact Prof. Dr. Emad Flear Aziz: emad.aziz@helmholtz-berlin.de.