Determining the chemical composition of sub-micrometer rock-forming minerals is still a challenging task. The electron probe micro-analyzer (EPMA) is considered the most accurate analytical way to obtain chemical data on amorphous and crystalline materials. However, performing EPMA analyses on sub-micrometer-sized grains is uncertain not recommended as the risk of obtaining analyses contaminated from the surrounding phases. A transmission electron microscope (TEM) equipped with an energy dispersive X-ray spectrometer (EDS) provides a greater spatial resolution, making it possible to obtain trustworthy chemical information on sub-micrometer-sized material. In this work, we present a fast and cheap data-reduction protocol for TEM-EDS chemical analysis, where k-factors derived experimentally for each element of interest and absorption correction are implemented. The results are compared with those determined using standardless and non-corrected TEM-EDS protocols. The k-factor for oxygen plays a fundamental role and its value should be calculated from compounds similar to the phase of interest. For absorption correction, the contribution of hydrogen during structural formula recalculation is taken into account, like a lower net valence of oxygen. The robustness of this protocol was tested by performing TEM-EDS analyses on white mica grains from metapelites, belonging to the Internal Ligurian Units exposed in the Northern Apennines, the chemical composition of which is well constrained. Such a protocol has proven to provide high-quality results from both statistical and crystallo-chemical perspectives. Remarkably, the tested data-reduction protocol for TEM-EDS analysis provided chemical compositions consistent with the EPMA results previously obtained from the same samples.

Authigenic chlorites and illites coexisting in clastic reservoir sandstones have been studied by energy dispersive X-ray spectroscopy (EDS) in the transmission electron microscope (TEM). All 16 samples studied are drill or sidewall cores from sandstones of relatively uniform age situated offshore Norway with burial depths ranging between 2400 m and 5000 m and representing temperatures between 90°C and 180°C. Chlorites and illites with authigenic equilibrium type texture and morphology were analyzed by EDS. Tetrahedral Al and octahedral Fe+Mg in chlorite increases with burial at the expense of Si and vacant octahedral positions in the chlorite structure. Illites show a clear increase in K. These factors indicate that a continuous chemical modification of these minerals takes place in the diagenetic interval studied through continuous dissolution and precipitation reactions.

We present here the analysis of the radiocarbon concentration and the components deposited on 2-year-old Pinus sylvestris L. needles collected in 2021, which were exposed to air contaminants for approximately two years. The needles were collected from seven sampling sites located near roads, households, and industrial factories in Silesia, the most industrialized part of Poland. The radiocarbon concentration was investigated using liquid scintillation spectrometry. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to quantitatively analyze the elements deposited on the surface of pine needles. The depletion of the radiocarbon concentration in pine needles relative to clean air was observed at most of the investigated sites. Although it has been observed that in the research area, the fossil fuel CO2 emission ranging from 0.4 to 3%, we cannot exclude that Suess effect may be underestimated due to biomass burning and mixing of the 14CO2 origin from different sources. A significant amount of silicon, nitrogen, and sulfur was commonly found in samples, Metal elements of Ca, Fe, Al, Mg, and K were also present in most samples. Heavier elements of Fe and Ti were present in higher concentrations only in needles obtained from sites nearer to the heat and power plant in Łaziska Górne.

Because the essential quality metrics of blast furnace slag are based on its oxide composition, the determination of chemical compositions of unhydrated slag grains in an aged concrete could be useful for understanding its past performance and in predicting the remaining service life of existing slag-bearing concrete. In this research, the authors explored the feasibility of using standard-based energy-dispersive X-ray spectroscopy (EDS) microanalysis, in tandem with electron imaging, as a tool for quantitative measurement of the chemical composition of blast furnace slag grains in cement/concrete. In the experimental study, seven concrete samples representing various service life durations were collected in the Netherlands. The microanalysis results of the samples revealed that the change in slag chemistry is insignificant for samples B (1985) to F (2006); however, elevated CaO and SiO2 contents are found in slag used for sample G (2015), opposite to that of Al2O3 and MgO. After discussing compositional characterization, the paper discusses favorable microanalysis protocols for acceptable elemental quantification accuracy. It was concluded that quantitative EDS microanalysis is a strong tool to characterize the chemical composition of unhydrated slag used in field concrete, which could potentially contribute to understanding the correlations between composition and long-term performance in slag concrete structures.

A common problem in analytical scanning electron microscopy (SEM) using electron backscatter diffraction (EBSD) is the differentiation of phases with distinct chemistry but the same or very similar crystal structure. X-ray energy dispersive spectroscopy (EDS) is useful to help differentiate these phases of similar crystal structures but different elemental makeups. However, open, automated, and unbiased methods of differentiating phases of similar EBSD responses based on their EDS response are lacking. This paper describes a simple data analytics-based method, using a combination of singular value decomposition and cluster analysis, to merge simultaneously acquired EDS + EBSD information and automatically determine phases from both their crystal and elemental data. I use hexagonal TiB2 ceramic contaminated with multiple crystallographically ambiguous but chemically distinct cubic phases to illustrate the method. Code, in the form of a Python 3 Jupyter Notebook, and the necessary data to replicate the analysis are provided as Supplementary material.

NeXL is a collection of Julia language packages (libraries) for X-ray microanalysis data processing. NeXLCore provides basic atomic and X-ray physics data and models including support for microanalysis-related data types for materials and k-ratios. NeXLMatrixCorrection provides algorithms for matrix correction and iteration. NeXLSpectrum provides utilities and tools for energy-dispersive X-ray spectrum and hyperspectrum analysis including display, manipulation, and fitting. NeXL is integrated with the Julia language infrastructure. NeXL builds on the Gadfly plotting library and the DataFrames tabular data library. When combined with the DrWatson package, NeXL can provide a highly reproducible environment in which to process microanalysis data. Data availability and reproducible data analysis are two keys to scientific reproducibility. Not only should readers of journal articles have access to the data, they should also be able to reproduce the analysis steps that take the data to final results. This paper will both discuss the NeXL framework and provide examples of how it can used for reproducible data analysis.

Low-Z nanocrystalline diamond (NCD) grids have been developed to reduce spurious fluorescence and avoid X-ray peak overlaps or interferences between the specimen and conventional metal grids. The low-Z NCD grids are non-toxic and safe to handle, conductive, can be subjected to high-temperature heating experiments, and may be used for analytical work in lieu of metal grids. Both a half-grid geometry, which can be used for any lift-out method, or a full-grid geometry that can be used for ex situ lift-out or thin film analyses, can be fabricated and used for experiments.

This work presents the microstructure of the cross-section of a newly developed Nb/Inconel 601 weld with particular attention paid to the continuity, morphology of the interface, and the microstructural changes within its vicinity. Both scanning (SEM) and transmission (TEM) electron microscopy techniques are excellent tools to analyze the microstructure that affects both mechanical and corrosion resistance properties of the obtained product. Grain size examination and their orientation together with the character of grain boundaries by the electron backscattered diffraction (EBSD) technique were performed followed by chemical composition determination across the interface with energy-dispersive X-ray spectroscopy (EDS) in SEM. Then, the microstructure observations of the mixed region located at the Nb/Inconel 601 interface using the TEM technique allowed its chemical and phase composition to be revealed.

This paper presents a proof of concept for the discrimination of several nanoparticle populations mixed in consumer products. The methodology proposes correlation of AFM, SEM, and EDS data to obtain structural and chemical information on each particle in a mixed population. To this end, emphasis is placed on sample preparation, imaging specifications for each instrument, and data correlation with adapted software.

Myrmekites occurring in monzodiorite from the Meichuan pluton in the Dabie ultrahigh-pressure metamorphic belt were investigated. The petrographic evidence demonstrates a metasomatic origin for myrmekite formation at the scale of individual alkali feldspar grains, and that the myrmekitic quartz and plagioclase matrix are generated simultaneously replacing precursor feldspar. Energy-dispersive X-ray spectroscopy and electron microprobe analysis indicate a low anorthite content in the narrow rim of host plagioclase near the myrmekite–alkali-feldspar interface. The Ca2+, Na+ proportion of hydrothermal fluids replacing precursor alkali feldspar is 1:5.4, calculated from the anorthite content of the inner part of the host plagioclase and the neighbouring alkali feldspar. Electron back-scattered diffraction was used to identify the crystallographic orientation of the myrmekitic quartz, plagioclase matrix and the precursor alkali feldspar. The crystallographic orientation relationships (110)Kfs//(11$\bar{2}\bar{1}$)Qtz, (20$\bar{1}$)Kfs//(11$\bar{2}$1)Qtz and [11$\bar{2}3]$Qtz//[001]Kfs between myrmekitic quartz and adjacent alkali feldspar were obtained from statistical analysis. No clear crystallographic orientation relationship between quartz and plagioclase was found. The growth of myrmekitic quartz is constrained by the precursor alkali feldspar rather than the simultaneously crystallised plagioclase. This research is helpful for understanding the intergrowth mechanism during metasomatism.

Adding Au to Pd nanoparticles (NPs) can impart high catalytic activity with respect to hydrogenation of a wide range of substances. These materials are often synthesized by reducing metallic precursors; hence, sonochemical and solvothermal processes are commonly used to anchor these bimetals onto thin supports, including graphene. Although similar NPs have been studied reasonably well, a clear understanding of structural characteristics relative to their synthesis parameters is lacking, due to limitations in characterization techniques, which may prevent optimization of this very promising catalyst. In this report, a strategic approach has been used to identify this structural and material synthesis correlation, starting with controlled sample preparation and followed by detailed characterization. This includes advanced scanning transmission electron microscopy and electron energy loss spectroscopy; the latter using a state-of-the-art instrumentation to map the distribution of Pd and Au, and to identify chemical state of the Pd NPs, which has not been previously reported. Results show that catalytic bimetal NP clusters were made of small zero-valent Pd NPs aggregating to form a shell around an Au core. Not only can the described characterization approach be applied to similar material systems, but the results can guide the optimization of the synthesis procedures.

The effects of cobalt ions on the precipitation of goethite in highly alkaline media were monitored using X-ray diffraction (XRD), Mössbauer, Fourier transform infrared (FTIR) and energy dispersive X-ray (EDS) spectroscopies and field emission scanning electron microscopy (FESEM) techniques. Tetramethylammonium hydroxide was used as a precipitating agent. The precipitates were collected after heating of the precipitation systems at 160ºC for 2 h. The XRD results showed the formation of goethite structure as a single phase up to r = 6.98 (where r = 100·[Co]/([Co]+[Fe])). Cobalt ferrite was found as an additional phase in the precipitates obtained at r = 9.09 and 13.04. Mössbauer spectroscopy showed the formation of solid solutions of α-(Fe,Co)OOH. The incorporation of cobalt ions into the goethite crystal structure was monitored by a decrease in the average hyperfine magnetic field (⟨Bhf⟩). The value ⟨Bhf⟩ decreased linearly up to r = 5.66, whereas a nonlinear dependence was obtained at r = 6.98 to 13.04. Infrared (IR) bands corresponding to the bending vibrations δOH and γOH were shifted from 892 to 903 cm–1 and from 797 to 800 cm–1, respectively, up to r = 6.98. Fourier transform infrared spectroscopy lacked the sensitivity to monitor the effects of cobalt ions, demonstrated by the Mössbauer analysis. Cobalt incorporation into the crystal structure of goethite induced a gradual elongation of α-(Fe,Co)OOH particles along the crystallographic c axis. The formation of α-(Fe,Co)OOH nanowires was shown at r ⩾6.98. These nanowires were ~700 nm long, whereas their diameter was ~15–20 nm. The majority of the cobalt ferrite particles were in the nanosize range, as observed by FE-SEM. On the basis of the Co/Fe ratio measured by EDS, it appears that the cobalt ferrite particles were not fully stoichiometric.

The ICDD has developed a microanalysis tool to help scientists identify minerals from their elemental analyses, most typically micro-XRF or a microprobe analysis. Many minerals have characteristic elemental profiles that can often distinguish the mineral from others by their composition differences. In Release 2016 ICDD® PDF-4 databases 20 670 unique compositions have been identified out of 45 497 mineral and mineral-related entries. The application utilizes several common features of PDF® databases to enhance correct identification, most notably those formulas are expressed in weight and atomic percent, data sets are classified by mineral nomenclature and structural classifications, and most minerals have associated atomic and molecular structures. These crystal structures are very useful in determining compositional variants and solid solutions. The ICDD has developed algorithms that are analogous to the search/match processes used for powder diffraction identification. Data can be input as either the element or common oxide. To test the algorithm and graphics interfaces we compared results from the microanalysis module to published data from the Smithsonian Microbeam reference mineral collection. The software correctly identified 24/28 minerals by the highest merit score in the algorithm. In two cases, an isoelemental mineral was identified and in two other cases, the specimens had more elements than the reference standards hindering positive phase identification.

In the development of dry self-lubricating composites, not only solid lubricant particle size and distribution are important, but also the correct selection of the solid lubricant characteristics, which should be stable, i.e. not reactive, during the whole processing. In this work, Fe+9 vol% h-BN composites were produced by uniaxial cold compaction and sintering, for which a reaction between h-BN and iron was detected after sintering at 1,150°C. The reaction phase was characterized by optical and scanning electron microscopy and identified by X-ray diffraction and energy-dispersive X-ray spectroscopy. The newly formed phase had high hardness when compared with the iron matrix. The resulting composites presented a high friction coefficient and high wear.

With the development of affordable aberration correctors, analytical scanning transmission electron microscopy (STEM) studies of complex interfaces can now be conducted at high spatial resolution at laboratories worldwide. Energy-dispersive X-ray spectroscopy (EDS) in particular has grown in popularity, as it enables elemental mapping over a wide range of ionization energies. However, the interpretation of atomically resolved data is greatly complicated by beam–sample interactions that are often overlooked by novice users. Here we describe the practical factors—namely, sample thickness and the choice of ionization edge—that affect the quantification of a model perovskite oxide interface. Our measurements of the same sample, in regions of different thickness, indicate that interface profiles can vary by as much as 2–5 unit cells, depending on the spectral feature. This finding is supported by multislice simulations, which reveal that on-axis maps of even perfectly abrupt interfaces exhibit significant delocalization. Quantification of thicker samples is further complicated by channeling to heavier sites across the interface, as well as an increased signal background. We show that extreme care must be taken to prepare samples to minimize channeling effects and argue that it may not be possible to extract atomically resolved information from many chemical maps.

The evolution of the energy dispersive spectrometer (EDS) from the lithium-drifted silicon detector [Si(Li)] to the silicon drift detector (SDD) has created new opportunities in the field of electron probe X-ray microanalysis. The SDD permits operation at significantly higher count rates than the Si(Li) and also provides a more stable energy scale. X-ray spectra captured by EDS can now be analyzed qualitatively or quantitatively under the same beam conditions as used for wavelength dispersive spectrometry (WDS). Standards-based quantitative EDS (SB-Quant-EDS) can thus provide analyses that are accurate and precise for an ever growing number of materials measurement problems. In this study, we analyze NIST research glasses with “known” nominal concentrations of titanium (Ti) and vanadium (V) to evaluate the external reproducibility of the SB-Quant-EDS technique in the presence of severe peak overlaps. We additionally analyze several naturally occurring oxide minerals by WDS and EDS simultaneously and evaluate the outputs of these two methods when quantifying the same analytical volume within the sample.

Scanning electron microscopy with energy-dispersive spectrometry has been applied to the analysis of various materials at low-incident beam energies, E0≤5 keV, using peak fitting and following the measured standards/matrix corrections protocol embedded in the National Institute of Standards and Technology Desktop Spectrum Analyzer-II analytical software engine. Low beam energy analysis provides improved spatial resolution laterally and in-depth. The lower beam energy restricts the atomic shells that can be ionized, reducing the number of X-ray peak families available to the analyst. At E0=5 keV, all elements of the periodic table except H and He can be measured. As the beam energy is reduced below 5 keV, elements become inaccessible due to lack of excitation of useful characteristic X-ray peaks. The shallow sampling depth of low beam energy microanalysis makes the technique more sensitive to surface compositional modification due to formation of oxides and other reaction layers. Accurate and precise analysis is possible with the use of appropriate standards and by accumulating high count spectra of unknowns and standards (>1 million counts integrated from 0.1 keV to E0).

This work deals with the determination of the mineralogical composition of three quartzite samples, selected as case study to verify the viability and accuracy of various experimental techniques commonly used in geometallurgy and petrography for the determination of the mineralogical composition of rock samples. The investigated samples are from the North-Eastern side of the Denali National Park (Alaska Range, USA). The mineralogical phase abundance of the samples was determined by digitally assisted optical modal point counting, scanning electron microscopy (SEM) + energy dispersive spectroscopy (EDS) modal and digital image analysis, normative calculation from bulk chemistry calculation, and modal Rietveld X-ray powder diffraction. The results of our study indicate that the results provided by modal optical and SEM digitalized counting seem less accurate than the others. The determination with EDS mapping was found to be inaccurate only for one sample. Agreement was found between the X-ray diffraction estimates and bulk chemistry calculation. For both modal optical and SEM digitalized counting, the statistics was probably insufficient to provide accurate results. The estimates obtained from the various methods are compared with each other in the attempt to attain general indications on the precision, accuracy, advantages/disadvantages of each method.

We report our effort to quantify atomic-scale chemical maps obtained by collecting energy-dispersive X-ray spectra (EDS) using scanning transmission electron microscopy (STEM) (STEM-EDS). With thin specimen conditions and localized EDS scattering potential, the X-ray counts from atomic columns can be properly counted by fitting Gaussian peaks at the atomic columns, and can then be used for site-by-site chemical quantification. The effects of specimen thickness and X-ray energy on the Gaussian peak width are investigated using SrTiO3 (STO) as a model specimen. The relationship between the peak width and spatial resolution of an EDS map is also studied. Furthermore, the method developed by this work is applied to study cation occupancy in a Sm-doped STO thin film and antiphase boundaries (APBs) present within the STO film. We find that Sm atoms occupy both Sr and Ti sites but preferably the Sr sites, and Sm atoms are relatively depleted at the APBs likely owing to the effect of strain.

Closed form analytical equations used to calculate the collection solid angle of six common geometries of solid-state X-ray detectors in scanning and scanning/transmission analytical electron microscopy are presented. Using these formulae one can make realistic comparisons of the merits of the different detector geometries in modern electron column instruments. This work updates earlier formulations and adds new detector configurations.