Journal of Electron Spectroscopy and Related Phenomena最新文献

Selective and label-free probing of drugs by scanning transmission X-ray microscopy (STXM) is applied along with hyperspectral imaging to probe topically applied drugs in human skin explants ex vivo. A comparison of data evaluation strategies is reported, which includes changes in optical density at selected photon energies in the O 1 s regime, linear combination modeling using reference spectra, as well as principal component and cluster analyses. It is shown that consistent results are obtained from linear combination modeling of reference spectra and changes in optical density. The dermal penetration of the anti-inflammatory drug rapamycin is investigated with high spatial resolution using a petrolatum-based formulation. For such well-known formulation the result of occlusion is investigated leading to drug uptake into corneocytes. Additional changes in drug penetration induced by weakening the skin barrier by the serine protease trypsin are also included. These results are discussed in comparison with the dermal penetration of other drug formulations. Finally, alternatives to present data acquisition strategies in STXM are discussed with respect to sub-sampling in combination with mathematical approaches, so that the full chemical and spatial information can be retrieved and radiation damage is minimized.

We report on the experimental investigation of single crystals of trans-[RuNOPy₄F](ClO₄)₂ (1) in its ground state (GS). The X-ray absorption spectroscopy (XAS) spectra measured at the N, O and F K-edges were compared to TDDFT calculations to identify and assign the absorption peaks, and to elucidate the structures of coordinated nitric oxide (NO). Based on a reasonable match of experimental and calculated spectra of GS, the N, O and F K-edges XAS spectra of Ru-ON (MS1) and Ru-η²-(NO) (MS2) isomers of 1 were calculated. According to the calculations, the energy or/and intensity of the 1 s→LUMO, LUMO+ 1 peaks of N, O or F K-edge changes significantly after GS isomerization to both MS1 and MS2. Current theoretical modeling of the NO linkage isomer in 1 is a background for the future investigation of isomerization process of NO by XAS methods. Since the investigated isomerization occurs in a variety of different nitrosyl complexes, obtained results can be extrapolated to a large family of transition metal nitrosyl compounds.

Spectromicroscopy refers to analytical methods that combine imaging and spectroscopy to provide detailed, spatially resolved analytical information about a sample, such as the type and quantitative spatial distributions of chemical components, geometric or magnetic alignment information, crystal structure, etc. The analysis of X-ray images and spectra (aXis2000) software described in this work provides a set of routines within a single, integrated, graphical-oriented package to read, display, manipulate and analyze spectromicroscopy data, with particular focus on soft X-ray spectromicroscopy methods such as scanning transmission X-ray microscopy (STXM), X-ray photoemission electron microscopy (XPEEM), scanning photoelectron X-ray microscopy (SPEM) and transmission X-ray microscopy (TXM). Here, this free software is described and compared to other software that can provide similar or complementary capabilities. Examples of spectromicroscopic analyses using advanced features of aXis2000 are provided.

A theoretical study of integral and differential cross sections as well as of spin-polarization effects is reported for elastic electron scattering by zinc atoms at collision energies up to 3 keV. It has been shown that a P-wave shape resonance appears in the low-energy range of the integral cross sections. Its energy is about 0.19 and 0.20 eV, while its width is about 0.309 and 0.356 eV for the j = 3/2 and j = 1/2 total angular momentum of the electron, respectively. The differential cross sections of scattering and the Sherman-functions $S(E,\theta )$ are computed by the parameter-free complex optical potential method. The calculated data are in a good overall agreement with the available experimental and theoretical data in the literature. The energy and angular positions have been located for five critical minima in the differential cross sections. The low-energy minimum is located at [6.63 eV; 102.34°], while the high-energy minimum is at [347.53 eV; 124.11°]. Ten points for the scattered electrons' total spin-polarization ($S=\pm 1$) have been found in the vicinity of the critical minima along with the energy and the angular widths of the spin-polarization peaks (where $\left|S\right|\ge 0.9$).

The spatially resolved ARPES (nanoARPES) is a development of conventional ARPES technique achieved with the focusing of light on the sample into the spot with submicron sizes. This development is used in research of essentially small samples, for example, heterostructures build of flakes of 2D materials, micro-crystals or polycrystalline samples, different crystal termination, domains in electronic structure. ANTARES is delivering the nanoARPES technique to user community since 2010, up to now the instrument was used with samples of various types, and that was useful to accumulate the specific experience. In this paper we report the current layout and actual performance of the ANTARES instrument at Synchrotron SOLEIL, as well as the most typical application areas. The most important and recent upgrades include focusing optics and in-operando setup. The new optical units deliver the increased flux on sample as well as the option to vary the photon energy. The in-operando setup offers the option of electrical connection to the sample being studied with nanoARPES, that promises various applications, where the most demanded now is the control of charge carrier density with applied voltage. This “gate-doping” is often applied to the heterostructures of 2D materials, that could be designed and build on purpose. The 2D heterostructures is probably the most typical field of application of the instrument, with or without in-operando option. At the same time the use case of the ANTARES instrument is still in the development by the realisation of new kinds of samples and of the new types of the experiments.

The development of advanced energy systems is essential for replacing fossil fuel-based societies, and progress in the fundamental understanding of solid-state energy materials has revolutionized this field. In particular, investigating the inhomogeneity of reactions in energy systems requires analysis at the level of individual particles, which are the smallest units in the system. Synchrotron-based scanning transmission X-ray microscopy (STXM) is a valuable tool for exploring reaction and degradation mechanisms, and providing nanoscale site-specific information on chemical and structural changes within single particles. In-situ/operando STXM is particularly useful for observing reactions under well-controlled conditions in real time, thus providing insights into local phenomena obscured by the ensemble effect. This review highlights the research achievements of in-situ/operando STXM in the field of energy materials and provides perspectives for advanced X-ray imaging techniques that can further enhance STXM capabilities.

With size reduction of active elements in microelectronics to tens of nanometers and below, the effect of surface and interface properties on overall device performance becomes crucial. High resolution spectroscopic and imaging techniques provide a metrological route for characterization of these properties relevant to device diagnostics and failure analysis. With its roughly 100 nm spatial resolution, superior surface sensitivity, and approximately 200 meV spectral resolution, scanning photoelectron microscopy (SPEM) stands out as a comprehensive tool to access the surface/interface composition of nanodevices, as well to provide chemical state designations and materials property evolutions upon treatment by thermal, electrical, chemical, radiative and other stimuli. Here we present a SPEM-on-device setup that combines X-ray spectromicroscopy with advanced NIST microhotplate technology to demonstrate new combined analytical and electrical measurements capabilities of this metrology platform for operando nanodevice characterization. Using model integrated SnO₂ nanowire (NW) chemiresistor devices, the chemically induced alterations in the chemical state of the nanowire surface are correlated to the observed conductance changes, thus directly testing the receptor and transduction mechanisms for SnO₂ NW conductometric chemical sensors.

Microscopy using the soft X-ray as an illumination source can integrate spectroscopy into images. This capability was implemented at Taiwan Light Source (TLS) in the early 2000s through two photoelectron-based microscopy stations whose imaging optics is either zone-plate (TLS 09A1) or electron lens (TLS 05B2). The microscopy project was later expanded into multiple stations and beamlines at Taiwan Photon Source (TPS) to take advantage of TPS’s low emittance. In this report, we summarize the activities of soft X-ray microscopy at TLS, followed by the status of microscopy stations under construction at beamline TPS 27A and 39A. The new lineup at TPS is to meet the scientific challenges ahead while carrying the existing activities forward. Both photoemission and transmission X-ray microscopy will be available at TPS.

We review the main developments and first commissioning experiments at the CARNAÚBA X-ray nanoprobe beamline, recently installed at the brand-new Sirius 4th-generation synchrotron radiation source at the Brazilian Synchrotron Light Laboratory (LNLS). The paper briefly discusses the X-ray nanoprobe instrument, emphasizing the first deployed experimental station TARUMÃ, and showcases preliminary results in a broad range of areas that benefit from diverse sample environments. Research domains like photovoltaics, photonics, electrocatalysis, geoscience, and agriculture are investigated from the viewpoint of chemistry, atomic structure, morphology, and redox dynamics phenomena covered by the beamline techniques. Finally, future capabilities are presented based on a new instrument under development.

Synchrontron radiation enabled recent measurement of the complete photoemission spectrum of acrylamide reported by Evangelisti et al. in Photochem. 2 (2022) 463. It seems to be a pity that calculation with the usually reliable ab initio method SAC-CI did not produce good agreement with experiment. In the present study, we use density functional theory methods in order to improve the agreement between experiment and theory. Such agreement helps to validate the DFT methods used. Our DFT results also suggest that two peaks in the N1s X-ray absorptiom spectrum have been incorrectly assigned.