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.
- BESSY II: How intrinsic oxygen shortens the lifespan of solid-state batteriesAlthough solid-state batteries (SSBs) demonstrate high performance and are intrinsically safe, their capacity currently declines rapidly. A team from the TU Wien, Humboldt-University Berlin and HZB has now analysed a TiS₂|Li₃YCl₆ solid-state half-cell in operando at BESSY II using a special sample environment that allows for non-destructive investigation under real operating conditions. Data obtained by combination of soft and hard X-ray photoelectron spectroscopy (XPS and HAXPES) revealed a new degradation mechanism that had not previously been identified in solid-state batteries. They have gained some surprising insights, particularly regarding the harmful role played by intrinsic oxygen. This study provides valuable information for improving design and handling of such batteries.
- Too old for research at 60? From nuclear physics to papyrus researchA career in science can be personally fulfilling. However, this also means accepting the unpredictable: research topics may no longer receive funding, and laboratories may close. Heinz-Eberhard Mahnke experienced this first-hand when he had to seek new challenges in his early 60s. Today, the 81-year-old is still active in research, using non-destructive measurement methods to examine ancient artefacts of inestimable cultural value. Antonia Rötger spoke with this extraordinary researcher, whose curiosity and drive are truly inspiring.
- Spintronics at BESSY II: Real-time analysis of magnetic bilayer systemsSpintronic devices enable data processing with significantly lower energy consumption. They are based on the interaction between ferromagnetic and antiferromagnetic layers. Now, a team from Freie Universität Berlin, HZB and Uppsala University has succeeded in tracking, for each layer separately, how the magnetic order changes after a short laser pulse has excited the system. They were also able to identify the main cause of the loss of antiferromagnetic order in the oxide layer: the excitation is transported from the hot electrons in the ferromagnetic metal to the spins in the antiferromagnet.