THz Electron Paramagnetic Resonance / THz Spectroscopy at BESSY II


  • Karsten Holldack Helmholtz-Zentrum Berlin für Materialien und Energie
  • Alexander Schnegg Helmholtz-Zentrum Berlin für Materialien und Energie



The THz beamline at BESSY II employs high power broadband femto- to picosecond long THz pulses for magneto-optical THz and FIR studies. A newly designed set-up exploits the unique properties of ultrashort THz pulses generated by laser-energy modulation of electron bunches in the storage ring or alternatively from compressed electron bunches. Experiments from 0.15 to 5 THz (~ 5 – 150 cm-1) may be conducted at a user station equipped with a fully evacuated high resolution FTIR spectrometer (0.0063 cm-1), lHe cooled bolometer detectors, a THz TDS set-up and different sample environments, including a superconducting high field magnet (+11 T - 11T) with variable temperature insert (1.5 K – 300 K), a sample cryostat and a THz attenuated total reflection chamber.  Main applications are Frequency Domain Fourier transform THz-Electron Paramagnetic Resonance (FD-FT THz-EPR), THz-FTIR spectroscopy and optical pump - THz probe time domain spectroscopy (TDS), with sub-ps time resolution.


Born, P., Holldack, K., & Sperl, M. (2015). Particle characterization using THz spectroscopy. Granular Matter, 17(5), 531-536.

Braggaglia, V., Schnegg, A., Calarco, R., & Holldack, K. (2015). Ultrafast THz Coherent Synchrotron Radiation Response of Phase Change Materials upon Laser Excitation. submitted (2015).

Dreiser, J., Pedersen, K. S., Schnegg, A., Holldack, K., Nehrkorn, J., Sigrist, M., . . . Waldmann, O. (2013). Three-Axis Anisotropic Exchange Coupling in the Single-Molecule Magnets NEt4[MnIII2(5-Brsalen)2(MeOH)2MIII(CN)6] (M=Ru, Os). Chemistry – A European Journal, 19(11), 3693–3701.

Dreiser, J., Schnegg, A., Holldack, K., Pedersen, K. S., Schau-Magnussen, M., Nehrkorn, J., . . . Waldmann, O. (2011). Frequency-Domain Fourier-Transform Terahertz Spectroscopy of the Single-Molecule Magnet (NEt4)[Mn2(5-Brsalen)2(MeOH)2Cr(CN)6]. Chemistry – A European Journal, 17(27), 7492–7498.

Forshaw, A. P., Smith, J. M., Ozarowski, A., Krzystek, J., Smirnov, D., Zvyagin, S. A., . . . Telser, J. (2013). Low-Spin Hexacoordinate Mn(III): Synthesis and Spectroscopic Investigation of Homoleptic Tris(pyrazolyl)borate and Tris(carbene)borate Complexes. Inorganic Chemistry, 52(1), 144-159.

Nehrkorn, J., Martins, B. M., Holldack, K., Stoll, S., Dobbek, H., Bittl, R., & Schnegg, A. (2013). Zero-field splittings in metHb and metMb with aquo and fluoro ligands: a FD-FT THz-EPR study. Molecular Physics, 111(18-19), 2696-2707.

Nehrkorn, J., Schnegg, A., Holldack, K., & Stoll, S. (2015). General Magnetic Transition Dipole Moments for Electron Paramagnetic Resonance. Physical Review Letters, 114, 010801.

Nehrkorn, J., Telser, J., Holldack, K., Stoll, S., & Schnegg, A. (2015). Simulating Frequency-Domain Electron Paramagnetic Resonance: Bridging the Gap between Experiment and Magnetic Parameters for High-Spin Transition-Metal Ion Complexes. The Journal of Physical Chemistry B, 119(43), 13816-13824.

Pedersen, K. S., Dreiser, J., Nehrkorn, J., Gysler, M., Schau-Magnussen, M., Schnegg, A., . . . Bendix, J. (2011). A linear single-molecule magnet based on [RuIII(CN)6]3-. Chemical Communications, 47, 6918-6920.

Pinkowicz, D., Southerland, H. I., Avendaño, C., Prosvirin, A., Sanders, C., Wernsdorfer, W., . . . Dunbar, K. R. (2015). Cyanide Single-Molecule Magnets Exhibiting Solvent Dependent Reversible “On” and “Off” Exchange Bias Behavior. Journal of the American Chemical Society, 137(45), 14406-14422.

Schnegg, A., Behrends, J., Lips, K., Bittl, R., & Holldack, K. (2009). Frequency domain Fourier transform THz-EPR on single molecule magnets using coherent synchrotron radiation. Physical Chemistry Chemical Physics, 11, 6820-6825.

Vogel, C., Stemann, J., Holldack, K., Sekine, R., Lipiec, E., & Adam, C. (2015). Thermal Treatment of Chromium(III) Oxide with Carbonates Analyzed by Far-Infrared Spectroscopy. Applied Spectroscopy, 69(10), 1210-1214.

Cite article as: Helmholtz-Zentrum Berlin für Materialien und Energie. (2016). THz Electron Paramagnetic Resonance / THz Spectroscopy at BESSY II. Journal of large-scale research facilities, 2, A51.