Journal Article Combining SEM-EDS and Micro-XRF-EDS Analysis: In-situ Search for Trace Mineral Phases in Meteorites Get access Roald Tagle, Roald Tagle Bruker Nano GmbH, Am Studio 2D, Berlin, GermanyBruker Nano GmbH, Am Studio 2D, Berlin, Germany Corresponding author: roald.tagle@bruker.com Search for other works by this author on: Oxford Academic Google Scholar Andrew H Menzies, Andrew H Menzies Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Stephan Boehm, Stephan Boehm Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Falk Reinhardt, Falk Reinhardt Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Christian Hirschle, Christian Hirschle Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Nigel Kelly Nigel Kelly Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 28, Issue S1, 1 August 2022, Page 2720, https://doi.org/10.1017/S1431927622010236 Published: 01 August 2022

Journal Article High-speed Micro-XRF Analysis of Rock Samples and Drill Cores Get access Andrew H Menzies, Andrew H Menzies Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Corresponding author: andrew.menzies@bruker.com Search for other works by this author on: Oxford Academic Google Scholar Roald Tagle, Roald Tagle Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Falk Reinhardt, Falk Reinhardt Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Christian Hirschle, Christian Hirschle Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Leonard J Schellkopf, Leonard J Schellkopf Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Nigel Kelly Nigel Kelly Bruker Nano GmbH, Am Studio 2D, Berlin, Germany Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 28, Issue S1, 1 August 2022, Pages 650–651, https://doi.org/10.1017/S1431927622003117 Published: 01 August 2022

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Concrete is an important material throughout history and has been used as a building material since the Mesopotamian ages. It became very popular with Greek and Roman builders. In addition, concrete can withstand immense pressure and has a high durability, it can be poured into almost any shape, and if reinforced with steel cable or mesh, it can bridge wide distances. However, concrete does weather with time. Under the right conditions, it can last thousands of years, nevertheless, as concrete is a mixture of many complex chemical compounds, its durability depends on environmental conditions. Saltwater, for example, leads to chemical reactions that can change the volume and lead to stress and strain in the concrete structure. Important reactions in understanding concrete weathering are the Alkali–Silica Reaction (ASR) and the Alkali–Carbonate Reaction (ACR), which are described elsewhere in detail1. Such reactions can cause the concrete to expand or contract and deform, depending on the materials within the concrete.

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the 'Save PDF' action button.

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In the classical approach of the fundamental parameter (FP) method, measured count rates are extracted from the observed spectrum by peak fitting or deconvolution and usually by subtracting the background, which is determined by numerical procedures. The quantification of an unknown sample is performed in an iterative procedure where those measured count rates are compared with computed fluorescence intensities, calculated with analytical equations.

We respond to the comment by W. Jark and D. Eichert on our earlier article concerning geometrical optics based data interpretation of grazing incidence X-ray fluorescence experiments. The potential of the alternative, diffraction based model proposed in the comment is recognized. However, weak points of this method, especially the one concerning its inapplicability to non-periodic structures, are also presented. We reply to the questions raised by the comment giving a more detailed explanation of the parameterization that was used to depict characteristic spectral features. Finally a simple experimental test that can be run to validate both methods is proposed.

Various 3-dimensional nano-scaled periodic structures with different configurations and periods deposited on the surface of silicon and silica substrates were investigated by means of the grazing incidence and grazing emission X-ray fluorescence techniques. Apart from the characteristics which are typical for particle- and layer-like samples, the measured angular intensity profiles show additional periodicity-related features. The latter could be explained by a novel theoretical approach based on simple geometrical optics (GO) considerations. The new GO-based calculations were found to yield results in good agreement with experiment, also in cases where other theoretical approaches are not valid, e.g., periodic particle distributions with an increased surface coverage.

Analytical methods with spatial or temporal resolution generates multidimensional data sets. These type of analytical results are generated very often because they allow a more detailed characterization of the analyzed material. Multidimensional data can be presented in different ways – as single point results, as distributions of the measured data for a single or several parameters of the data set or as distribution of evaluated data. In particular in case of micro-Xray fluorescence the data sets are distributions of elemental intensities. They contain a large number of information and can give an interesting overview for a large sample area of an inhomogeneous material.

X-ray Standing Wave (XSW) is a well established formalism for modelling Grazing Incidence X-ray Fluorescence (GIXRF) experiments. However, when probing nanostructured surfaces with complex morphology the effects of the interaction of the XSW with structure elements need to be investigated. This is not always easy and sometimes even not possible. In the present work a novel approach employing Geometrical Optics (GO) calculations is proposed. The model is employed for simulations of two different types of nano-particles distributed on a flat surface. It is shown that GO simulation yields results with good agreement when compared to absolute measurements even when XSW deteriorates.

A novel ultra-high vacuum instrument for X-ray reflectometry and spectrometry-related techniques for nanoanalytics by means of synchrotron radiation has been constructed and commissioned. This versatile instrument was developed by the Physikalisch-Technische Bundesanstalt, Germany's national metrology institute, and includes a 9-axis manipulator that allows for an independent alignment of the samples with respect to all degrees of freedom. In addition, a rotational and translational movement of several photodiodes as well as a translational movement of an aperture system in and out of the beam is provided. Thus, the new instrument enables various analytical techniques based on energy dispersive X-ray detectors such as reference-free X-ray fluorescence analysis (XRF), total-reflection XRF, grazing-incidence XRF in addition to optional X-ray reflectometry measurements or polarization-dependent X-ray absorption fine structure analyses. With this instrument samples having a size of up to 100 mm × 100 mm can be analyzed with respect to their mass deposition, elemental or spatial composition, or the species in order to probe surface contamination, layer composition and thickness, the depth profile of matrix elements or implants, the species of nanolayers, nanoparticles or buried interfaces as well as the molecular orientation of bonds. Selected applications of this advanced ultra-high vacuum instrument demonstrate both its flexibility and capability.

The analysis of the elemental composition of aerosol particles by non-destructive grazing incidence X-ray fluorescence analysis (GIXRF) is possible if the particles are deposited on a flat substrate. If those particles exhibit surface areas parallel to the substrate surface, under certain experimental conditions, total reflection of incident X-rays might arise also at those sites thereby preventing X-rays from penetrating the particles. For a reliable quantitative analysis, this effect and the interaction with the X-ray standing wave field (XSW) has to be further investigated in detail. To study the effects occurring when nanoscaled objects are probed with GIXRF, artificial nanostructures of known size, shape and composition have been manufactured on flat silicon wafer surfaces, with the intention to simulate deposited nanoscaled aerosol particles. A reference-free quantification of the deposited mass was performed employing a simple model for the propagation of the XSW through the sample material. Depending on the quality of the manufactured structures, good agreement between nominal masses and measured values could be stated. Only moderate agreement was found for samples that were more difficult to manufacture. GIXRF measurements yield information on the physical dimensions of the structures which are well in line with results obtained by a combination of scanning electron microscopy and energy-dispersive X-ray spectrometry (SEM/EDX). The presented quantification model, which is based on existing software for XSW calculations, can be transferred to environmental nanoparticles sampled directly from the aerosol phase. All measurements were performed in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at BESSY II using well-characterized monochromatic synchrotron radiation and calibrated instrumentation.

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The semiconductor band gap of the Cu(In,Ga)Se2 (CIGSe) compound can be varied by the In to Ga ratio. This composition variation determines the photovoltaic properties of CIGSe thin films. Their composition depth profile has to be optimized in order to obtain maximum efficiencies in solar cell applications. Synchrotron-radiation-based X-ray fluorescence (XRF) analysis under grazing incidence conditions provides non-destructive access to the compositional depth profile of the CIGSe thin films and, hence, represents a new non-destructive method, which does not require well-characterized standards for calibration purposes. Based on an analytical description of the physical processes, fluorescence line intensities of the specimen can be calculated by using fundamental atomic parameters. The general suitability of the method for determining depth gradients in CIGSe thin films is first shown by calculations. Reference-free XRF test measurements were carried out at the FCM beamline in the PTB laboratory at BESSY II. X-ray fluorescence was induced by photon excitation at energies of 4.0keV and 10.5keV, respectively, using various shallow incident angles. The calculations and the experimental measurements show that even small differences in the Ga/In profile may be distinguished, indicating that grazing incidence XRF is a promising tool for a non-destructive characterization of compositional depth profiles. Further refinement of the operational parameters may contribute to the sensitivity of the method.

The formation of Self-Assembled Monolayers (SAMs) by specific organic molecules with appropriate anchor groups on semiconductor surfaces may be used to probe the chemical state and quality of the surface or to achieve surface passivation. Molecules with thiole anchor groups are capable to bond via a Ge-S bond to hydrogen-terminated germanium surfaces. We have prepared SAMs of alkylthioles with different head groups on germanium. Since the surface preparation of germanium is not well understood and developed the controlled preparation of an oxide-free completely H-terminated surface turned out as major challenge and prerequisite for SAMs formation of alkylthioles. Several approaches have been studied. The HF treatment provided the most promising results. Nevertheless the maximum coverage by SAMs achieved was 50 % depending on the preparation conditions. The characterization of the germanium surface prior to and after SAMs formation has been performed by AFM, XPS and TXRF.

The formation of self-assembled monolayers (SAMs) by suitable organic molecules with appropriate anchor groups on semiconductor surfaces may be used either to probe both the chemical state and the quality of the surface or to achieve surface passivation. Molecules with thiol anchor groups are able to bond to hydrogen-terminated germanium surfaces (Ge-S bond). We have prepared SAMs of alkylthiols with trifluoroacetate head groups on germanium. The germanium surface prior to and after SAMs formation has been characterised by Near-Edge X-Ray Absorption Fine Structure spectroscopy (NEXAFS) with synchrotron radiation in the PTB laboratory at BESSY II. We succeeded in assigning S-NEXAFS peaks to the Ge-S bond formed during self-assembly and were able to distinguish between different fluorine species via F-NEXAFS.