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.
- Magnon momentum microscopy: A new window into nanoscale spin-wavesAn international team lead by the Max Born Institute has developed a new type of momentum microscopy to image magnons — the quanta of collectively excited spins — directly in two-dimensional reciprocal space using soft X-rays. Measurements have taken place at BESSY II and PETRA III, first author ist the HZB physicist Steffen Wittrock. Owing to its remarkable sensitivity, simplicity, and access to nanometer-scale wavelengths, this novel technique establishes a powerful and versatile platform for exploring nonlinear magnon interactions, which are promising for future computing schemes.
- X-ray analysis reveals overpainted fascist symbolsErich Mercker was a successful painter during the Nazi era and in the years that followed. After 1945, he covered up Nazi symbols in at least one of his paintings. With an interdisciplinary team, physicist Dr Ioanna Mantouvalou reports on this study in the Nature Journal Heritage Science.
- AI agents deliver results – but do they reason scientifically?A research team co-led by Kevin Maik Jablonka from the Helmholtz Institute for Polymers in Energy Applications Jena (HIPOLE Jena) and N. M. Anoop Krishnan from the Indian Institute of Technology Delhi has developed Corral, a new benchmark for AI agents in science. The preprint “AI scientists produce results without reasoning scientifically” has been published on arXiv (https://doi.org/10.48550/arXiv.2604.18805). The analysis shows that current systems can execute scientific workflows and deliver results; however, they often do not follow the basic principles of scientific testing and reasoning.