Topic of the report: breaking the materials barrier: atom probe topography, an emerging tool for chemical analysis of soft matter and complex interfaces.
Informant: Prof. Dr. Guido Schmitz (Professor, University of Stuttgart, Germany)
Reporting time: Friday, October 23rd, 2026, 10: 30am-11: 30am.
Location: Room 303, Building 38, Wushan Campus
Organizer: School of Mechanical and Automotive Engineering
Brief introduction of the speaker:
Guido Schmitz, Professor of Materials Physics and Director of Institute of Materials Science, University of Stuttgart, Germany. In 1994, he received his Ph.D. from the University of Gö ttingen, and in 2000, he was qualified as a professor in this school. He used to be a postdoctoral researcher at UCLA and a professor at the University of Mü nster in Germany. Since 2013, he has been a chair professor at the University of Stuttgart. Professor Schmitz has long been engaged in the research on the solid-state reaction of nanostructured materials, grain boundary diffusion, interface structure and stability, and is an internationally renowned expert in the field of atomic probe chromatography. He has made many pioneering achievements in the research and development of instruments, analysis of frozen liquids and soft materials, three-dimensional volume reconstruction methods and thermodynamic statistical measurement. He is currently the editor-in-chief of the International Journal of Materials Research, a fellow of the International Field Emission Society, and has won the Werner-Köster Award from the German Materials Society.
Summary of report:
Atom probe tomography is a method of microscopic analysis that is already well-established in the study of hard materials. It is based on controlled fi eld desorption and stands out by combining single-atom sensitivity with a 3D volume reconstruction. Particular strongholds are the accurate measurement of chemical segregation to grain boundaries and interfaces in nanostructured matter. Our recent efforts push forward volume reconstruction methods, the quantum mechanics simulation of the evaporation process and the statistical understanding of chemical fluctuations which even enables a direct mea surement of Gibbs energy. We desire to break the materials limitations towards the analysis of soft matter and polymeric materials. Meanwhile, nanometric needles are produced from frozen liquids, even from pure water. Studies are performed with aqueous solutions, liquids of short alkanes, liquid crystals and self-assembling monolayers. The talk first gives an introduction into the physical principles of the method: high field nanoscienc e, field desorption, time of flight spectroscopy and volume reconstruction. Then it addresses current problems and research fields that currently opens up new fields of ap plication: The field desorption of liquids and organic and soft materials and their dependence on field or laser intensity. The complex mechanisms of f ield desorption from frozen water surfaces and molecular organic liquids are elucidated by DFT and Monte-Carlo simulation. New concepts of volume recon struction, and statistical methods are introduced to derive physically realistic tip shapes from the data set, the Gibbs energy of mixing in binary alloys and to evaluate the quality of the analysis of battery electrodes.
