Systematic and Collaborative Approach to Problem Solving using X-ray Photoelectron Spectroscopy

Collaborators from the UK, France, Germany, Canada, Denmark and the USA – including our technical manager, Dr David Morgan – have published a recent article in Applied Surface Science Advances [1], highlighting the methodology developed from many years of interaction between junior and senior X-ray Photoelectron Spectroscopy (XPS) practitioners using […]

Arsenic

Arsenic is primarily analysed using the As(3d) region, which can overlap with the Ta(5p1/2) signal.  Generally observed as an oxide or in GaAs, the As(3d) region has a spin-orbit splitting of 0.7 eV, with an intensity ratio of 0.7, as opposed to the expected 0.67. Recording the As(2p3/2) region is […]

Argon Clusters vs Monatomic Ions

Figure 1. Argon ions (left) and argon clusters (right) impinging on a surface Monatomic ions are excellent at cleaning and profiling ‘hard’ samples, such as metallic or ceramic samples. Whilst used for sometime in the SIMS community, gas cluster ion beams (GCIB) also termed argon clusters, have recently been employed […]

Reflection Electron Energy Loss Spectroscopy (REELS)

REELS is a surface analysis technique in which a surface is bombarded with an electron beam (typically ≤ 1 keV) and the energy distribution of the reflected electrons is measured. [1] The energy distribution contains features whihc correspond to discrete losses of energy of the reflected electrons due to excited […]

Rhenium

Typically considered to be one of the most stable elements due to its high melting and boiling points, rhenium is often found in nickel based superalloys, but also finds use in olefin metahtesis and reforming catalysis. Rhenium can exhibit multiple oxidation states, with +7, +6, +4 and +2 the most […]

Angle Resolved XPS (ARXPS)

Not to be confused with Angle-resolved photoemission spectroscopy (ARPES), angle-resolved XPS (ARXPS) is a technique which varies the emission angle at which the electrons are collected and in doing so, enabling electron detection from different depths by exploting the inelastic mean free path (IMFP) of the photoelectrons. ARXPS is especially […]

Analysis Depth in XPS & IMFP

The inelastic mean free path, or IMFP (λ), is defined as the average distance an electron with a given energy travels through a solid before losing energy by inelastic collision. Approximately 68 % of all photoelectrons will come from within a depth of λ, whereas the majority (99.7 %) of […]

Detection Limits in XPS

Generally the detection limits in XPS range from 0.1 to 1 at%., but there are instances there these limits can be improved or be considerably worse. In 2014, Alex Shard at NPL has published an article investigating the detection limits of elements in over 6000 binary systems for Al and […]

Argon

Argon, commonly encountered as an ion from ion etching experimetns, such as depth profiles, is only typically seen implanted after sputter cleaning or depth profilesalthough the gas-phase spectra as seen in figure 1, have been recorded at near ambient pressures (NAP-XPS) [1]. Implanted argon is more likely to be detected […]

Experimental Reporting

Reporting the methodology of your data acquisition and analysis is highly important in any publication, be it a research paper, thesis or internal report. The inclusion of experimental parameters and conditions allow the reader to make an informed decision to the data presented and highlight any possible issues which may […]