BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:Dr. Claudia Cancellieri & Dr. Lars Jeurgens : Depth-Resolved Chemi cal and Electronic Structure of Surfaces and Interfaces by Combined Lab-Ba sed XPS and HAXPES DTSTART:20260227T143000 DTEND:20260227T153000 DTSTAMP:20261004T132423Z UID:c11c37c20554a3412b95ea0db9659c92b6e1e69a9e197670d98692c9 CATEGORIES:Conferences - Seminars DESCRIPTION:Dr. Claudia Cancellieri & Dr. Lars Jeurgens\,\nLaboratory for Joining Technologies & Corrosion\, Empa\,\nSwiss Federal Laboratories for Materials Science and Technology\, Dübendorf\,\nSwitzerland\nAbstract : H ard X-ray photoelectron spectroscopy (HAXPES) provides access to photoelec trons with much higher kinetic energies than conventional XPS\, which not only increases the probing depth but also gives access to an extended bind ing energy range for chemical state analysis. By combining XPS and HAXPES\ , specific core-level photoelectron lines can be measured at different pro bing depths and closely matched with the fixed probing depth of a correspo nding Auger line. This enables chemical state analysis at near-constant pr obing depth by monitoring the so-called Auger parameter (AP)\, which is in dependent of charging and (electronic) band-banding effects [1].\nThis sem inar presents a series of case studies illustrating the versatility of lab -based HAXPES in combination with conventional XPS for chemical state anal ysis across a broad range of functional materials used in corrosion protec tion\, catalysis\, nanojoining\, diffusion barrier layers\, energy materia ls\, and solid-state battery technologies. For example\, AP analysis of Al 2O3 and TiO2 thin films prepared by different synthesis methods (e.g. atom ic layer deposition (ALD)\, anodization\, thermal oxidation) proves to be a powerful tool for tracing oxide polymorphism in the crystalline state\, as well as tiny variations of the local coordination spheres between diffe rent amorphous states [2\,3]. Changes in the local chemical states of the cations and anions in functional oxides\, as evidenced from the measured A P shifts\, can be correlated with variations in their optical and dielectr ic properties. Measured AP shifts of amorphous Al₂O₃ films with differ ent densities and hydrogen contents (as grown by ALD) have been successful ly predicted by atomistic simulations using machine-learning interatomic p otentials [2\, 3]. As such\, the hydrogen-induced changes in the distribut ion of 4/5/6-fold local coordination spheres of the Al cations in the amor phous Al₂O₃ films could be disclosed [2\,3]. Lab-based XPS/HAXPES has also been applied to develop procedures for efficient surface cleaning of Li₇La₃Zr₂O₁₂ solid electrolytes for solid-state batteries [4]. F or metallic multilayers used in e.g. nano-joining technologies\, measured AP shifts are shown to be a sensitive probe of electronic charge transfer at buried interfaces [5]. Very recently\, an integrated electrochemical– UHV approach combined with dual-beam XPS/HAXPES has been implemented to st udy the interaction of atomic hydrogen with passive oxides on steels.\n[1] S. Siol\, et al.\, Concepts for chemical state analysis at constant probi ng depth by lab-based XPS/HAXPES combining soft and hard X-ray sources\, S urface & Interface Analysis 52 (2020) 802.\n[2] C. Cancellieri et al.\, Ef fect of Hydrogen on the Chemical State\, Stoichiometry and Density of Amor phous Al2O3 Films Grown by Thermal Atomic Layer Deposition\, Surface and I nterface Analysis 56 (2024) 293.\n[3] S. Gramatte et al.\, Unveiling hydro gen chemical states in supersaturated amorphous alumina via machine learni ng-driven atomistic modeling\, npj Computational Materials 11 (2025) 170.\ n[4] H. Zhang et al.\, On high-temperature thermal cleaning of LLZO solid- state electrolytes\, ACS Applied Energy Materials 6 (2023) 6972.\n[5] C. C ancellieri et al.\, Chemical and Electronic Structure of Buried W/Cu\, W/C r\, and W/Mo Interfaces by In Situ XPS/HAXPES Auger Parameter Analysis\, S urface and Interface Analysis 57 (2025) 357.\n\n\nBio : \nDr. Claudia Canc ellieri is a group leader/ research scientist at Empa in the Laboratory fo r Joining technologies and corrosion. In 2008 she obtained her PhD in Phys ics at École Polytechnique Federal in Lausanne (EPFL)\, specializing in P ulsed Laser Deposition growth of cuprates and oxide thin films under strai n. During her first post-Doc at the University of Geneva\, she focused on the growth and characterization of complex oxide interfaces. She continued the investigation of this topic at the synchrotron Swiss Light Source\, P aul Scherrer Institute where she extensively used spectroscopy techniques to derive the electronic band structure of buried complex oxide interfaces . Her current research topics include the investigation of interfaces and their chemical stability in relation to microstructure\, defects\, interna l stress and electronic properties of functional materials interfaces incl uding multilayers systems and thin amorphous oxides on metals.\n\nDr. Lars Jeurgens obtained his PhD in materials sciences at the Delft University o f Technology (NL) in 2001. After working for the Dutch technology foundati on (STW)\, he moved to the Max Planck Institute for Metals Research in Stu ttgart (DE) in 2003\, leading a research group on “Reactions and Phase T ransformations at Surfaces and Interfaces”\, while being responsible for the surface analysis services at the institute. His research was honoured with the Masing Gedächtnispreis of the Deutsche Gesellschaft für Materi alkunde (DGM) in 2008. Lars joined the Empa\, as the head of the laborator y for “Joining Technologies and Corrosion”\, in 2012. His research int erests comprise the surface and interface engineering of metals\, alloys\, oxides and their coating systems for emerging nano-joining technologies a nd corrosion management\, Since 2020\, his laboratory runs the only lab-ba sed Hard X-ray Photoelectron Spectrometer in Switzerland. Accordingly\, hi s recent research focusses on chemical state studies of functional oxide f ilms by combing soft and hard X-ray Photoelectron Spectroscopy\n\n  LOCATION:Tseuzier https://plan.epfl.ch/?room==I17%204%20K2 https://epfl.zo om.us/j/65378030944 STATUS:CONFIRMED END:VEVENT END:VCALENDAR