Associate Professor Madeleine Ramstedt
Department of Chemistry, Umeå University, Sweden
Abstract
Biological samples such as microbial cells are in their natural condition highly hydrated. Traditionally, surface analysis of these types of samples have been performed on freeze-dried specimens.
Read more
However, the drying procedure may introduce artifacts and alter the chemical surface composition. In order to avoid this, we developed methodologies for analyzing microbial samples using cryogenic XPS and have, through the years, applied this to bacterial cells, biofilms, bacterial vesicles, fungal cells, microalgae and viruses. This talk will describe the methodology used and illustrate the types of data that we have obtained on selected microorganisms.
Bio
Assoc. Prof. Madeleine Ramstedt received her PhD in inorganic surface chemistry from Umeå University in Sweden in 2004.
Read more
She has a postdoc from EPFL in Switzerland and the University of Cambridge in the UK, focusing on polymer surface chemistry and bacterial interactions. She became an assistant professor at Umeå University in 2008 and an associate professor in 2012. She has worked with XPS since 2000 and investigated surface chemistry of microbial systems since 2009.
Professor Philippe Marcus
CNRS (Centre National de la Recherche Scientifique), France
Physical Chemistry of Surfaces, Institut de Recherche de Chimie Paris, Chimie ParisTech, France
Abstract
This lecture with focus on a surface analytical approach of corrosion and protection of metals and alloys. Oxide films, such as passive films, occupy a central role in corrosion and protection because without such surface oxides nearly no metal or alloy could be used in our environment.
Read more
Therefore it is essential to understand the oxide growth, their protective properties, the origin of defects responsible for their local breakdown. This requires the use of surface analytical techniques including XPS, ToF-SIMS, STM.
The best case is when the oxide forms spontaneously on the metal surface as it does on e.g. aluminium, titanium, stainless steels, and new highly corrosion resistant alloys such as High Entropy Alloys. Oxide layers can also be deposited (e.g. by ALD) on less corrosion resistant alloys.
These various aspects will be presented and exemplified in this lecture, and future trends will be discussed.
Bio
Prof. Philippe Marcus is Director of Research at CNRS (Centre National de la Recherche Scientifique) and Head of the Research Group of Physical Chemistry of Surfaces of Institut de Recherche de Chimie Paris, Chimie ParisTech, France.
Read more
His field of research is surface science and corrosion science, with an emphasis on metals/alloys and thin oxide layers at the nanoscale.
Prof. Marcus has published over 400 papers in scientific journals. His h-index is 87, and number of citations 27507 (source: Google Scholar, February 2024). He was a laureate of an ERC Advanced Grant (2017–2023), and he has given over 150 invited lectures at International Conferences. He serves or served on the editorial board of five international journals.
Prof. Marcus has received several international awards and honors, including the 2005 Uhlig Award from the Electrochemical Society, the 2015 Corrosion Medal of the European Federation of Corrosion and the 2017 Olin Palladium Award from the Electrochemical Society. He is a Fellow of the Electrochemical Society and the International Society of Electrochemistry. He was Chair of the Gordon Research Conference on Aqueous Corrosion (2006), President of the European Federation of Corrosion (2008–2012), Chair of the Electrochemical Materials Science Division of the International Society of Electrochemistry, and Chair of the Europe Section of the Electrochemical Society (2021–2023). He is currently Chair of the EFC Working Party on Surface Science and Mechanisms of Corrosion and Protection, Chair of the International Steering Committee for the European Conferences on Applications of Surface and Interface Analysis, and President of the French Corrosion Society (CEFRACOR). Prof. Marcus is an elected member of the European Academy.
Dr. Donald R Baer
Pacific Northwest National Laboratory (PNNL), Richland WA, USA
Abstract
The value of information obtained using XPS has fueled significant growth in its use in multiple disciplines and by a new generation of analysts as well as ‘casual’ users less familiar with the method.
Read more
Accompanying this increased use and changes in the nature of the user community are i) increased presence of erroneous data analysis in literature and ii) fewer analysts taking full advantage of the types of information that can be extracted from well-constructed XPS experiments. This talk will suggest information that experienced XPS analysts can pass along to less experienced XPS users to address both issues. First, the status of several efforts being undertaken to address faulty analysis, and incomplete reporting will be described. These address analysis issues and lack of needed information and parameter reporting. Second, several useful but underused approaches to XPS data collection and analysis will be described.
Examination of literature shows a significant amount of faulty XPS data analysis, often related to peak fitting, and significantly incomplete reporting of data and analysis parameters needed to assess result reliability or enable results replication. Recent publications highlight common errors in the effort to encourage analysts to avoid them as well as enable readers and reviewers to recognize them. Analyses also indicate that most publications using XPS ask one or more of three interrelated questions: i) What elements are present? ii) How much of each element is on the surface? iii) What are the chemical states of the elements present? Although very appropriate and important uses of XPS, there is a wider range of material and sample information can be obtained that enables XPS to address several analysis needs.
An incomplete list of accessible information includes, sample polarizability and dielectric constants, chemically resolved electrical measurements, local electric field and potentials, band offsets and bending, the nature of electrical double layers and local charge dynamics, and changes in microbe cell walls in response to external stimuli. Common XPS analyses assume that the analyzed surface layer is uniform and ignore the impact of sample structure has on XPS signals. Information contained within XPS spectra can provide information about elemental distribution in the surface region, and information about coating thickness, uniformity, and size of nanoparticles. The talk will highlight two approaches that require specialized instrumental capabilities (application of AC or DC fields and cryoXPS) and other approaches primarily involve data analysis (Auger parameter, band information, D-band use, and ‘background’ signals).
Bio
Dr. Donald R Baer is a Laboratory Fellow Emeritus at Pacific Northwest National Laboratory (PNNL) in Richland WA.
Read more
His current activities include mentoring early career staff at PNNL and working on several journal projects related to reliable use and reporting of surface analysis measurements. These include serving as guest editor of a collection of papers on reproducibility challenges and solutions focused on surface analysis methods.
For more than 40 years Dr. Baer’s research focused on the impact of surfaces and interfaces on material properties including leading projects on the impact of impurities on mineral dissolution and growth, the ability of nanoparticles on the breakdown of groundwater contaminants and their influence on survival of biological systems. Because of the need for quantitative information for theoretical models he became involved in the development of ISO and ASTM standards for reliable and quantitative surface characterization. He helped establish the Environmental Molecular Sciences Laboratory, a US Department of Energy User Facility, where he served as science lead for surface and interfaces.
Professor Eduard Hryha
Centre for Additive Manufacturing – Metal (CAM2), Chalmers University of Technology, Gothenburg, Sweden
Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, Sweden
Abstract
Metal powder constitutes the most common feedstock used in metal additive manufacturing (AM), including powder bed fusion (laser beam PBF-LB, and electron beam – PBF-EB), binder jetting (BJT) and powder blown directed energy deposition (DED).
Read more
Even though the same alloys systems are often used for these technologies, they have different requirements to the powder feedstock when it comes to its physical and chemical characteristics and utilize different size fractions of the metal powder. In addition, this metal powder is exposed to very different conditions during the AM manufacturing cycle in case of different AM technologies. However, importance of powder properties, specifically powder surface chemistry and its changes during powder manufacturing, handling and AM processing is often overlooked. Hence, changes in powder properties during manufacturing cycle and its impact on the final component properties differ significantly.
Metal powder used for additive manufacturing is characterized by large surface area of the powder that leads to high surface reactivity. This, in combination with the alloy composition, will determine powder sensitivity to the powder manufacturing method, handling and AM processing. Powder surface chemistry is initially determined by powder manufacturing method and alloy composition. This initial chemical composition is, however, not stable, and progressively changes with time in dependance on powder handling and processing by metal additive manufacturing. These changes in powder surface chemistry during powder reuse have a strong impact on powder quality and processability by specific AM technologies. This talk summarizes recent experimental observations and thermodynamic simulations of the changes in powder surface chemistry during the whole life-cycle of metal powder: from its manufacturing through powder handling and AM processing by variety of powder-based metal AM technologies. Generic model of the powder degradation in dependance on initial powder properties and alloy composition when processed by different AM processes, is elaborated. Effect of the reused powder on the defect formation during AM processing and its impact on material properties is discussed.
Keywords: powder for AM, powder surface chemistry, XPS, AES, nano-SIMS, powder manufacturing, powder degradation, powder reuse.
Bio
Eduard Hryha is Professor in Powder Metallurgy and Metal Additive Manufacturing at the Department of Industrial and Materials Science, Chalmers University of Technology, Sweden.
Read more
He is also director of the Competence Centre for Metal Additive Manufacturing – Metal (CAM2: https://www.chalmers.se/en/centres/cam2) which involves more than 30 national and international research and industrial partners focusing on powder-based metal additive manufacturing (AM). He received his MSc in Applied Physics from Uzhorod National University in Ukraine in 2003 and PhD in Materials Science from IMR SAS in Slovakia in 2008.
Professor Sven Tougaard
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
Abstract
Quantitative characterization of nanostructures by analysis of the inelastic background in photoelectron spectroscopy (XPS and HAXPES) is now a widely used method.
Read more
[1] In the talk, we report on recent advancements of this method. First, we discuss the application to characterize core-shell nanoparticles (CSNPs) and show that both the shell thickness and its heterogeneity can be accurately determined, and it also correctly proves if the shell material fully encapsulates the core or if part of the core is uncoated [2]. Further, we recently showed how the method can be applied to correct ambient pressure XPS very accurately for the spectral distortion caused by the gas [3].
The only input in the method, besides the IMFP, is the cross section for inelastic electron scattering. For cases with stacks of layered materials that have widely different cross sections, this quantity is taken as the weighted average of the involved materials. [4] For cases where the involved cross sections are unknown, we recently showed that an optimized cross section, that is determined as part of the fitting procedure, can reliably be determined without any knowledge of the sample composition [5].
The method is non-destructive, and the probing depth is considerably larger than the usually quoted 3 IMFP because the inelastically scattered electrons originate from larger depths than the electrons in the peak and it is typically ~8 IMFP but can be ~20 IMFP in cases where the background can be followed over several hundred eV. The latter is often the case with HAXPES because the separation between deep lying core electrons can be much larger compared to conventional XPS. With HAXPES, the photo electron energy and thereby the IMFP and the probing depth is also increased and several examples with analysis of structures at greater than 100 nm depth have been reported [4,6]. Since lab based HAXPES is now commercially available it is being installed in many labs and its application in nanotechnology is expected to increase considerably.
Detailed tutorial videos of several of the examples discussed in the talk are available in [7].
[1] ST, J Vac Sci Technol A. 2021;39:011201 https://doi.org/10.1116/6.0000661;
[2] A. Müller et al, Surf Interface Anal. 2020;52(11):770 https://doi.org/10.1002/sia.6865
[3] ST, M. Greiner, Appl Surf Sci. 2020;530:147243. https://doi.org/10.1016/j.apsusc.2020.147243
[4] C. Zborowski, O. Renault, ST. et al J. Appl. Phys 124 (2018) 657
[5] C. Zborowski, ST., Surf Interface Anal. 2021;1–9 https://doi.org/10.1002/sia.7020
[6] B. F. Spencer et al. Appl. Surf Sci (2021) 541, 148635, https://doi.org/10.1016/j.apsusc.2020.148635
[7] ST. Tutorial videos; https://zenodo.org/search?q=tougaard
Bio
Prof. Sven Tougaard received a PhD in experimental and theoretical material science and surface physics at the University of Southern Denmark in 1979.
Read more
He was a postdoc in the USA and Germany (1978–84) and has been a professor at the University of Southern Denmark since 1984 (Emeritus since 2023). He founded QUASES-Tougaard Inc. (1994) which develops software for characterization of surface nanostructures by XPS and optical properties by REELS. He received the Rivière Prize awarded by the UK Surface Analysis Forum in 2007, “for work which has been judged outstanding in its continuing and lasting contribution to surface analysis”, and the Albert Nerken Award by the American Vacuum Society in 2012 “for contributions to the development of improved methods to characterize thin-film nanostructures by XPS”. He has conducted and participated in several international projects, published over 230 scientific papers which are cited more than 9000 times with an h-index = 47, and presented more than 60 invited talks. He is on the Steering Committee for ECASIA and serves on the editorial board for: J. Electron Spectroscopy (1990–2012), Surface and Interface Anal. (since 1990), J. Surface Analysis (since 1994), and Surface Science Spectra (since 1995).
Dr. Julia Maibach
Department of Physics, Chalmers University of Technology, Sweden
Abstract
Electrode/electrolyte interfaces are likely the most important and least understood components of Li-ion and next-generation batteries. Improving the understanding of interphases in batteries will undoubtedly lead to breakthroughs in the field.
Read more
However, obtaining chemical and electronic information with high interface sensitivity is challenging since these interfaces and interphases are typically buried between a solid electrode and liquid electrolyte. Traditionally, evaluating those interphases therefore involves ex situ surface sensitive techniques, even though ex situ sample manipulation is undesirable due to the interphases’ dynamic and reactive nature [1].
To resolve this issue, we use near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS). With this technique, the vacuum constraints of classical UVH-based XPS are relieved and solid/liquid interfaces can be studied. Combing NAP-XPS with specially designed operando setups to study the electrode/electrolyte interface under electrochemical bias, we gain more realistic information on the reactions between electrode and electrolyte.
In this contribution, I will review the journey from first applications of NAP-XPS to battery systems to identifying solid-electrolyte interphase (SEI) formation on model electrodes. As steps along the way I will present NAP-XPS characterizations of electrodes and electrolytes [2,3], tracking electrochemical potential differences over the solid/liquid interface in model battery systems under working conditions [4] and identifying electrode lithiation mechanisms [5].
[1] J. Maibach, J. Rizell, A. Matic, N. Mozhzhukhina, ACS Materials Lett., 2023, 5, 2431-2444.
[2] J. Maibach, I. Källquist, M. Andersson, S. Urpelainen, K. Edström, H. Rensmo, H. Siegbahn, and M. Hahlin, Nat. Commun., 2019, 10, 1-7.
[3] P.M. Dietrich, L. Gehrlein, J. Maibach, A. Thissen, Crystals, 2020, 10, 1056 .
[4] I. Källquist, F. Lindgren, M.-T. Lee, A. Shavorskiy, K. Edström, H. Rensmo, L. Nyholm, J. Maibach, M. Hahlin, ACS Appl. Mater. Interfaces, 2021, 13, 32989–32996.
[5] I. Källquist, T. Ericsson, F. Lindgren, H. chen, A. Shavorskiy, J. Maibach, M. Hahlin, ACS Appl. Mater Interfaces, 2022, 14, 6465-6475.
Bio
Dr. Julia Maibach is an assistant professor in Materials Physics at the Department of Physics at Chalmers University of Technology in Gothenburg, Sweden.
Read more
She earned her doctorate at TU Darmstadt in Germany in 2014 and spent a postdoctoral period at Uppsala University in Sweden, where she began her work on battery interfaces. With a prestigious Young Investigator grant from the Federal Ministry of Education and Research in Germany, Dr. Maibach started her independent scientific career in 2017 at Karlsruhe Institute of Technology before joining Chalmers in 2022, where she continues to research and teach electrode/electrolyte interfaces in rechargeable batteries.
Professor John F Watts FREng
University of Surrey, Guildford, UK
Abstract
Over the last fifty years a number of higher energy X-rays sources have been suggested as alternatives for the usual AlKα source found in the first commercial XPS systems, and still the standard anode material for XPS today.
Read more
This paper reviews the development of a number of such sources, predominantly in the author’s laboratory, and the rationale behind the desire to extend the standard binding energy range of XPS. The achromatic sources SiKα, ZrLα and TiKα are described along with monochromatic sources AgLα and CrKβ, both based on the standard quartz monochromator geometry but taking higher orders of diffraction. The driving force for much of this development was the desire to probe deeper core levels and associated CCC Auger transitions. These can be combined into initial (ξ) or final (α) state Auger parameters as described in much of the early work. The highest energy source considered is the CuKα source based around an external X-ray tube, which provide much insight into the electronic structure of steels by measurement of the Fe1s and FeKLL peaks. The last decade or so has seen a significant increase of interest in HAXPES, and all manufacturers of turn-key XPS instruments offer HAXPES options of one form or another, and there are three dedicated HAXPES systems commercially available, which will be briefly described.
Bio
John Watts is Professor of Materials Science at the University of Surrey, UK. Prof. Watts trained as a materials scientist and has been carrying out surface analysis in support of materials science investigations since the mid-1970s.
Read more
Initially by XPS followed by AES and then ToF-SIMS from the early 1990s. He received his PhD from the University of Surrey in 1981 and a DSc in 1997, he was elected a Fellow of the Royal Academy of Engineering in 2014. He has supervised over 60 doctoral students and has some 460 publications in the open literature. He is editor-in-chief of the journal Surface and Interface Analysis and chairs the BSI committee on Surface Chemical Analysis, CII/60.
Professor Wolfgang S.M. Werner
Vienna University of Technology, Austria
Abstract
The status quo of quantitative nanoanalysis using medium energy electrons will be briefly reviewed, demonstrating the impressive progress which has been made over the past fifty years.
Read more
This is in stark contrast to the understanding of the interaction of low energy electrons (LEEs) with surfaces which is rapidly gaining attention due to its importance for a variety of processes on the nanoscale: LEEs are not only essential for nanoscale analysis such as microscopy, CD metrology or attosecond physics but also act as agents inducing physico-chemical processes as in, e.g., electron lithography, electron beam induced deposition, astrochemistry and, last but not least, DNA-bond breaking induced by high energy ionising radiation striking biological tissue. Improvement in this field is complicated by the lack of benchmark experiments specifically designed to obtain information on individual physical parameters or processes.
In the present talk, a recently proposed experimental approach will be described in which the quantitative knowledge of the medium energy range is used to gain information about the (poorly understood) low energy range. This is done by using medium energy primary electrons as messengers of the depth of creation of low energy secondaries. Measuring the secondary electron intensity as a function of depth of creation, the attenuation law in the low energy range is quantified.
In the case of polymethylmethacrylate, it is found that the attenuation law is non-exponential, but is rather made up of two exponential functions, corresponding to two different groups of electrons playing a role in the energy dissipation process. The attenuation lengths of both groups are measured and essentially agree with a theory used for decades in astrophysics ––albeit with units expressed in nm rather than lightyears–– and providing electron attenuation lengths in the range between 0 eV and relativistic energies.
Bio
Wolfgang S.M. Werner is Professor of Physics at Vienna University of Technology in Austria. His main field of research is electron spectroscopy, in particular, the quantitative interpretation of electron spectra for surface analysis.
Read more
He led the development of the NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA) and presently, an artificial intelligence (AI) tool for quantitative interpretation of XP-spectra in the framework of the EUSpecLab Marie-Curie ITN project is under implementation. Energy dissipation processes as well as the transport and the emission of low energy electrons (LEEs) near solid surfaces was the focus of the SIMDALEE2 ITN Marie Curie project coordinated by Prof. Werner. This is an interdisciplinary research topic where the group of Prof. Werner contributed measurement of optical and electronic properties via electron scattering experiments along with spectroscopy with correlated electron pairs for a detailed understanding of the mechanism of secondary electron emission.
Dr Anna Regoutz
Department of Chemistry, University College London, UK
Abstract
Metal hydrides hold significant promise in various hydrogen-related technologies, encompassing energy storage, hydrogen compression, and hydrogen sensing.
Read more
Although metal hydrides appear simple compared to many other energy materials, understanding the electronic structure and chemical environment of hydrogen within them remains a key challenge. This work presents a new analytical pathway to explore these aspects in technologically relevant systems using Hard X-ray Photoelectron Spectroscopy (HAXPES) on thin films of two prototypical metal dihydrides: YH2−δ and TiH2−δ.[1] By taking advantage of the tunability of synchrotron radiation, a non-destructive depth profile of the chemical states is obtained using core-level spectra. Combining experimental valence band spectra collected at varying photon energies with theoretical insights from density functional theory (DFT) calculations, a description of the bonding nature and the role of d versus sp contributions to states near the Fermi energy are provided. Moreover, a reliable determination of the enthalpy of formation is proposed by using experimental values of the energy position of metal s band features close to the Fermi energy in the HAXPES valence band spectra.
[1] C. Kalha, L. E. Ratcliff, G. Colombi, C. Schlueter, B. Dam, A. Gloskovskii, T.-L. Lee, P. K. Thakur, P. Bhatt, Y. Zhu, J. Osterwalder, F. Offi, G. Panaccione, A. Regoutz, “Revealing the Bonding Nature and Electronic Structure of Early-Transition-Metal Dihydrides”, PRX Energy, 3, 013003, 2024, https://doi.org/10.1103/PRXEnergy.3.013003
Bio
DI Dr Anna Regoutz is Lecturer in Materials Chemistry at University College London and Visiting Scientist at Diamond Light Source.
Read more
She holds a D.Phil. in Inorganic Chemistry from the University of Oxford. Her research focuses on materials for electronic devices, including power electronics, flexible electronics, and biosensors. She specialises in the development of X-ray photoelectron spectroscopy methods, particularly leveraging hard X-rays to access interfaces and bulk properties. Dr Regoutz’s awards include the Royal Society of Chemistry’s Joseph Black Award (2020) and the element Praseodymium in IUPAC’s Periodic Table of Chemists (2019). She has been featured in the Merck Next Great Impossible Campaign and the Leading Light series of Diamond Light Source.
Sweden Meetx AB is the conference bureau handling the conference secretariat for the ECASIA 2024 conference.
E-mail: ecasia2024@meetx.se
Phone: +46 31 708 86 90
Registration opens: January 2024
Abstract submission deadline – April 5, 2024
Poster submission deadline – May 20, 2024
Early Bird Registration deadline – April 30, 2024
Conference Dates: 9-14 June 2024
