GaN is one of many materials which are difficult to analyze with the conventional Al Kα X-ray source due to a strong overlap between the N 1s core line and the Ga LMM Auger series. This brings difficulties with accurate quantification and also chemical state assignment. In this applications note, GaN was analyzed using different X-ray excitation sources with the aim of shifting the binding energy position of the Ga LMM Auger series to prevent its interference with the N 1s region. Automation of changing between the Al Kα and Ag Lα excitation sources when using the Kratos AXIS Supra+ is an added benefit.
The aim of this investigation was to characterise the performance of the gas-cluster ion source (GCIS) for the depth profiling of thick organic multi-layer materials. The sample is composed of 25 repeating units of polystyrene (PS) and polyvinylpyrrolidine (PVP) PS = 288 ± 1.3 and PVP = 328 ± 7 nm on a glass substrate. It has been considered challenging to depth profile thick samples (>1 micron) of soft materials due to the changes which occur under sus-tained X-ray irradiation and bombardment of charged projectiles, however, in this study we describe a methodology to eliminate these issues. The use of fast acquisition, snapshot spectroscopy and sample rotation during etching is presented.
Valence level photoelectron spectra (VLPS) were acquired for the material MoS2 using soft X-ray and deep UV photon energies. VLPS were acquired for both as-received and Argon cluster cleaned surfaces.
Using a combination of surface analysis tools, different polymer materials were analysed using the Kratos AXIS Supra+. A common issue with XPS analysis is that the C 1s envelope can look relatively similar for different polymer materials, making them difficult to distinguish using XPS alone. Plasmon features, such as the π-π* transition, which give information related to the sp2 content of a material are also concealed by shifts between different C chemical states. Here, a combination of XPS, UPS and REELS are used as complimentary tools to help understand the chemistry of several polymer materials.
UPS analysis of (semi)conducting samples allows the measurement of the work function of a material. Combined with XPS, this is a powerful combination of techniques to gain information about the valence structure of the surface. Here, a thin film, hybrid organic-inorganic lead bromide perovskite is analysed using a Kratos AXIS spectrometer. A comparison of the data is made after the removal of adventitious carbon with the Gas Cluster Ion Source (GCIS) to interpret how the work function of the material is affected.
XPS was used to characterize the surface chemistry of layered thin film materials, using monochromated Al Kα (1486.6 eV) X-rays to gain quantitative chemical information from the uppermost 10 nm of the surface. In this study, we illustrate how ARXPS is used as a more surface sensitive approach to probe only the topmost 1-3 nm of a material, and how one can utilize Maximum Entropy Method (MEM) software to recreate a concentration depth profile from the resulting data. How the re-moval of contamination effects the resulting MEM model fit is also explored following gentle sputter cleaning using the GCIS.
In late 1975 a special UHV XPS instrument incorporating many novel features was supplied to the UK Central Energy Generation Board (CEGB). This instrument was further developed into the latest electron spectrometer, the ES300, which was produced with excitation sources and vacuum pumping according to a customer's individual requirements. A comprehensive data system DS-300 was also launched with the ES300.
From these specifications we can see that unlimate performance of the ES300 was defined as 20,000 cps at 0.92 eV FWHM for the Ag 3d5/2 peak.
Rechargeable metal-based batteries (Li, Na and Al) are among the most versatile platforms for high-energy storage. Unfortunately however there are several pitfalls for these energy storage systems, one of which is deposition and dendrite formation during repeated cycles of charge and discharge. Many studies have been performed in search of a dendrite-free, deposition-free system for lithium batteries using novel materials such as 3D structures and carbon nanofibers.[1,2] Here we will explore the distribution of Lithium in different chemical environments on electrode surfaces. We employ conventional surface analysis techniques (XPS) to yield large area, quantitative, information regarding the distribution of surface species. To explore the lateral and depth distribution of Li we also utilise XP imaging and Argon cluster depth profiling.
Strip coating materials are commonly used in optic applications for the removal of grease and small particulates form the surfaces of delicate materials. Typically these include mask gratings, laser optics, telescope lenses and refractors. A clear red solution consisting of a blend of polymers is applied using a small brush and is then left to set. Once set, the polymer coating is peeled away leaving a pristine surface free of particulates.