Courses
Price: 200 EUR (Regular) / 150 EUR (Phd Student)
Sunday 13 September 2026
09:00–12:00
Professor Watts has been working continuously in the field of applied surface science since the late 1970s and has published some 470 papers and 2 books in this topic area. He has made important contributions to the interfacial chemistry of adhesion and other commercial and fundamental aspects of materials science. He was awarded his PhD in 1981, and a DSc for his contributions to surface analysis and adhesion science in 1997. He has successfully supervised over 70 doctoral students and 25 MSc students. He was President (2008-10) of The Adhesion Society Inc and has received the Society’s two senior awards; the Robert L Patrick Fellowship (2006) The 3M Prize for Excellence (2008). He was awarded the British Vacuum Council Prize and Yarwood Medal in 2009, the Rivière Prize of the UK Surface Analysis Forum in 2010 and the degree of Docteur Honoris Causa (DUniv) from the Université Paris Diderot in 2011. He was elected to the Fellowship of The Royal Academy of Engineering in 2014, In 2017 he received the Prix Dedale of the Section Francaise de l’Adhesion of SFV. He is chair of the BSI Committee on Surface Chemical analysis and Editor-in-Chief of the Wiley journal Surface and Interface Analysis.
Currently Professor of Materials Science in the School of Engineering he heads a research group active in the application of surface analysis methods (XPS, AES/SAM. ToF-SIMS and SPM) to investigations in materials science. HAXPES has been an ongoing interest since the early 1980s (AgLα), culminating in work with the novel X-ray sources CrKβ and CuLα, applied to investigations of the electronic structure of metallic alloys.
X-ray Photo-electron Spectroscopy
These lectures will introduce the basic principles of XPS, arguably the most widely used of the surface chemical analysis techniques, and describe the instrumentation employed. The cornerstone of XPS is the ability to provide chemical state information via the so-called XPS chemical shift and this will be described for a number of elements along with X-ray induced Auger transitions (X-AES), observed for about a third of the elements in the conventional XPS survey spectrum. The combination of XPS and X-AES peaks to provide an Auger Parameter, providing chemical state information which is independent of electrostatic charging, and in favourable cases provides structural information, will be introduced. Quantification of XPS spectra is an important feature of the techniques and is available on all commercial datasystems. The principles behind quantification processes will be described. The analysis depth of XPS is ca. 5 nm, but compositional depth profiling is an important aspect of XPS. This can be achieved by non-destructive methods (background analysis, angle resolved XPS and higher energy X-ray sources) or sputter profiling by energetic elemental or cluster ions (usually argon). The wide use of such methods in surface analysis investigations indicates the versatility of the technique. The analysis area in XPS on modern instruments varies from a diameter of around 1 mm2 to a few micrometres. At the lower spot sizes, it is feasible to build up an XPS map of a selected region of the specimen. This and other approaches to imaging XPS will be described in detail.
In addition to what one could consider conventional XPS, there have been two important developments in commercial systems; hard XPS (known as HAXPES) and near ambient pressure XPS (NAP-XPS), which allows non-vacuum compatible materials (such as biological specimens) to be examined and gas-solid surface reactions to be followed in real time, of great importance to the catalysis community. Current commercial systems available for HAXPES and NAP-XPS will be briefly reviewed.
Throughout the lectures case studies will be provided drawn from examples in the literature, mainly from the University of Surrey laboratory.
J F Watts, J Wolstenholme, “An introduction to surface analysis by XPS and AES. 2nd Edition” Published by John Wiley & Sons Ltd, Chichester UK, (2020).
12:00–13:00
Lunch
13:00–16:00
Professor Watts has been working continuously in the field of applied surface science since the late 1970s and has published some 470 papers and 2 books in this topic area. He has made important contributions to the interfacial chemistry of adhesion and other commercial and fundamental aspects of materials science. He was awarded his PhD in 1981, and a DSc for his contributions to surface analysis and adhesion science in 1997. He has successfully supervised over 70 doctoral students and 25 MSc students. He was President (2008-10) of The Adhesion Society Inc and has received the Society’s two senior awards; the Robert L Patrick Fellowship (2006) The 3M Prize for Excellence (2008). He was awarded the British Vacuum Council Prize and Yarwood Medal in 2009, the Rivière Prize of the UK Surface Analysis Forum in 2010 and the degree of Docteur Honoris Causa (DUniv) from the Université Paris Diderot in 2011. He was elected to the Fellowship of The Royal Academy of Engineering in 2014, In 2017 he received the Prix Dedale of the Section Francaise de l’Adhesion of SFV. He is chair of the BSI Committee on Surface Chemical analysis and Editor-in-Chief of the Wiley journal Surface and Interface Analysis.
Currently Professor of Materials Science in the School of Engineering he heads a research group active in the application of surface analysis methods (XPS, AES/SAM. ToF-SIMS and SPM) to investigations in materials science. HAXPES has been an ongoing interest since the early 1980s (AgLα), culminating in work with the novel X-ray sources CrKβ and CuLα, applied to investigations of the electronic structure of metallic alloys.
Secondary Ion Mass Spectrometry
Traditionally SIMS has been divided into two, almost separate, fields of endeavour; dynamic SIMS (DSIMS) and static SIMS (SSIMS). Although in recent years the division has become somewhat blurred it is useful to take the two versions, which have the same fundamental process at their heart, as a starting point. DSIMS uses a continuous ion beam and collects selected ions as the material is sputtered, to provide a compositional depth profile, where depth resolution is of paramount importance. In SSIMS the goal is to acquire an analysis of the surface layers, thus a much lower ion fluence is used, the goal being that no more than 1% of a monolayer is removed during analysis. For DSIMS an magnetic sector mass spectrometer is the analyser of choice whilst for SSIMS a form of time-of-flight mass spectrometer is preferred.
This course will introduce the basic principles of ion emission, and ion sources that are used in commercial systems. One aspect of SIMS that must always be borne in mind when considering SIMS spectra is the matrix effect and examples will be provided to show how this phenomenon can lead to potentially misleading results. There are a number of ways in which a modern SIMS instrument can be operated, to provide area spectra, mass selected images and depth profiles. In commercial systems this will be acquired as a large dataset and the required information extracted by post-processing. Polymer SIMS is an important application for the technique but the extensive fragmentation that takes place during ion emission makes the analysis somewhat challenging, although in principle it is possible to produce a molecular weight distribution of a polymer by ToF-SIMS, using cationisation techniques. The spectral resolution is particularly important in SSIMS as the ability to resolve components very close in the mass spectrum, e.g. 28SiH (m/z = 28.9847) and 29Si (m/z = 28.9765) can only be achieved with a high-resolution spectrometer. The spatial resolution is equally, if not more important, with the best performance being achieved with liquid metal ion sources, based on low melting point metals, with bismuth and gallium being particularly important. The bismuth source is more popular as it can generate small cluster ions (Bi3 to Bi7) with the potential to improve performance on some materials. In static SIMS, depth profiling is achieved by either using the primary source in the continuous mode (some ToF-SIMS systems pulse the primary source) or using an ancillary source such as Cs+ or one based on an inert gas, such as argon, where both elemental ions and clusters can be produced. Massive gas cluster ions for depth profiling are particularly beneficial for polymers as they have a much lower damage than their elemental counterparts.
As SIMS is such an information-rich technique multivariate analysis procedures have become very popular as a route to getting the most from a dataset. Principal component analysis (PCA) and non-negative matrix factorisation (NMF) are two approaches that will be introduced briefly and illustrated applied to organic systems.
J F Watts, J Wolstenholme, R P Webb, “Secondary ion mass spectrometry” in Characterization of Materials, Ed E N Kaufman, John Wiley & Sons Inc, Hoboken, NJ, USA, pp2058-2090, (2012).
Dr Gustavo F. Trindade is a Senior Scientist and Science Area Leader of the National Centre of Excellence in Mass Spectrometry Imaging (NiCE-MSI) at the UK's National Physical Laboratory (NPL). He has 15 years of experience with SIMS, more than 50 published papers and leads OrbiSIMS metrology at NPL since 2021. He has recently chaired the 101st IUVSTA Workshop on high-performance SIMS instrumentation and machine learning for complex data (101st IUVSTA Workshop). He is a Vickerman Prize holder and was featured as one of CellPress Matter’s 35 researchers under 35 tackling challenges in materials science.
Advanced analysis of SIMS data
Modern SIMS instruments are capable of obtaining three-dimensional information with high spatial resolution of a material with information as rich as a full mass spectrum at every voxel of the 3D dataset, thus generating very large and complex datasets. These high-resolution data provide new challenges and opportunities for multivariate analysis (MVA), machine learning (ML) and artificial intelligence (AI) approaches. The lecture will cover SIMS data structure and how to pre-process it, detail the more established MVA methods in the SIMS community and introduce some recent novel approaches using ML and AI.