Largest magnetic anisotropy of a molecule measured at BESSY II
THz-EPR setup in the experimental hall of BESSY II. © HZB
The magnetic properties of the investigated bismuth complex (center) were investigated using THz-EPR spectroscopy at BESSY II. The method uses electromagnetic radiation from the THz to the infrared range in combination with high magnetic fields. © HZB
At the Berlin synchrotron radiation source BESSY II, the largest magnetic anisotropy of a single molecule ever measured experimentally has been determined. The larger this anisotropy is, the better a molecule is suited as a molecular nanomagnet. Such nanomagnets have a wide range of potential applications, for example, in energy-efficient data storage. Researchers from the Max Planck Institute for Kohlenforschung (MPI KOFO), the Joint Lab EPR4Energy of the Max Planck Institute for Chemical Energy Conversion (MPI CEC) and the Helmholtz-Zentrum Berlin were involved in the study.
The research involved a bismuth complex synthesized in the group of Josep Cornella (MPI KOFO). This molecule has unique magnetic properties that a team led by Frank Neese (MPI KOFO) recently predicted in theoretical studies. So far, however, all attempts to measure the magnetic properties of the bismuth complex and thus experimentally confirm the theoretical predictions have failed.
This important step has now been achieved by using THz electron paramagnetic resonance spectroscopy (THz-EPR) at the synchrotron radiation source BESSY II, which is operated by the HZB in Berlin.
“The results show in a fascinating way that our method can be used to determine extremely high values of the magnetic anisotropy with high accuracy. Through our cooperation with scientists from fundamental research, we are thereby making a great step forward in the understanding of this class of materials,” says Tarek Al Said (HZB), first author of the study, which was recently published in the renowned Journal of the American Chemical Society.
- 3D magnetic field experiment at BESSY II takes spintronics a step further(Fe0.63Ni0.3Pd0.07)3P or FNPP is a magnetic material that exhibits complex magnetic structures even at room temperature. This makes the material of interest for spintronics, a field that could enable data processing with significantly lower energy consumption. One potential application is novel magnetic memory devices. However, generating and modifying the desired structures in a controlled manner remains a challenge to date. A new study led by HZB has now taken a step forward in this regard. They demonstrated at the worldwide unique VEKMAG-Station at BESSY II, that a tiny external B-field in the plane of the magnetic patterns is sufficient to change them.
- Confirmed figures for the first time: Investments in BESSY are worthwhile for Berlin and GermanyAn impact analysis by DIW Econ demonstrates the scientific and economic value of BESSY II. Every euro invested yields three euros for Germany and as much as ten euros for the State of Berlin. Furthermore, the study provides an economic forecast for the construction of BESSY III.
The impact analysis was presented on 3 September 2026 to Dr Henry Marx, State Secretary for Science and Research in the Berlin Senate. He supports the investment and is a strong advocate for BESSY III. - Detailed insights at BESSY II into the oxidation processes of copperBefore pure copper oxide builds up, complex superstructures such as ‘29’CuxO, are formed. The new results on the '29' CuxO superstructure have relevance for catalyst research and corrosion protection in the development of safe copper containers for nuclear waste repositories.