Humboldt Fellow new addition to Aziz team
Dr. Tristan Petit joins the Aziz-Team. Foto: T.Petit
Simulated view of a nanodiamond. © T. Petit
Starting June 1st, Dr. Tristan Petit will be joining Prof. Dr. Emad Flear Aziz’ team for a two-year postdoc. His Humboldt Foundation Fellowship for Postdoctoral Researchers gave Petit the option to choose his German scientific host. Ultimately, he decided on the Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) that was set up by Aziz. Says Petit: “I really wanted to be on Aziz’ team as they have a lot of collective expertise with spectroscopy in water.”
26-year-old Tristan Petit earned his Ph.D. degree at the Ecole Normale Supérieure de Cachan, France, back in March of this year. His doctoral work at the Diamond Sensors Laboratory (CEA), Gif-sur-Yvette, focused on nanodiamond surface modifications to evaluate their biomedical potential. Nanodiamonds could make good “drug cabs” as they have low toxicity and their surfaces can be easily functionalized for the transport of other molecules.
Although to date, the interactions between water molecules and nanoparticles remain unclear. Petit has made it his mission to get to the bottom of these interactions: He is planning on using soft X-ray spectroscopy to study water-based dispersions of nanodiamonds “in situ” on a microjet. This may provide important clues about how these special nanoparticles behave under physiological conditions, in other words, in the body. “Thanks to the unique Lixedrom experimental setup, we’re able to conduct experiments that can’t be done anywhere else really. Ultimately, that was a strong motivating factor for me to come to Berlin,” admits Petit.
- Fascinating archaeological find becomes a source of knowledgeThe Bavarian State Office for the Preservation of Historical Monuments (BLfD) has sent a rare artefact from the Middle Bronze Age to Berlin for examination using cutting-edge, non-destructive methods. It is a 3,400-year-old bronze sword, unearthed during archaeological excavations in Nördlingen, Swabia, in 2023. Experts have been able to determine how the hilt and blade are connected, as well as how the rare and well-preserved decorations on the pommel were made. This has provided valuable insight into the craft techniques employed in southern Germany during the Bronze Age. The BLfD used 3D computed tomography and X-ray diffraction to analyse internal stresses at the Helmholtz-Zentrum Berlin (HZB), as well as X-ray fluorescence spectroscopy at a BESSY II beamline supervised by the Bundesanstalt für Materialforschung und -prüfung (BAM).
- Element cobalt exhibits surprising propertiesThe element cobalt is considered a typical ferromagnet with no further secrets. However, an international team led by HZB researcher Dr. Jaime Sánchez-Barriga has now uncovered complex topological features in its electronic structure. Spin-resolved measurements of the band structure (spin-ARPES) at BESSY II revealed entangled energy bands that cross each other along extended paths in specific crystallographic directions, even at room temperature. As a result, cobalt can be considered as a highly tunable and unexpectedly rich topological platform, opening new perspectives for exploiting magnetic topological states in future information technologies.
- MXene for energy storage: More versatile than expectedMXene materials are promising candidates for a new energy storage technology. However, the processes by which the charge storage takes place were not yet fully understood. A team at HZB has examined, for the first time, individual MXene flakes to explore these processes in detail. Using the in situ Scanning transmission X-ray microscope 'MYSTIIC' at BESSY II, the scientists mapped the chemical states of Titanium atoms on the MXene flake surfaces. The results revealed two distinct redox reactions, depending on the electrolyte. This lays the groundwork for understanding charge transfer processes at the nanoscale and provides a basis for future research aimed at optimising pseudocapacitive energy storage devices.