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Multimodal imaging and spectroscopy like concurrent scanning transmission X-ray microscopy (STXM) and X-ray fluorescence (XRF) are highly desirable as they allow retrieving complementary information. This paper reports on the design, development, integration and field testing of a novel in situ atomic force microscopy (AFM) instrument for operation under high vacuum in a synchrotron soft X-ray microscopy STXM–XRF end-station. A combination of μXRF and AFM is demonstrated for the first time in the soft X-ray regime, with an outlook for the full XRF–STXM–AFM combination. [ABSTRACT FROM AUTHOR]

A series of nine new soft salts based on two platinum(II) complexes, namely ([Pt(C^N)(CN)2]−[Pt(C^N)(en)]+) (en = ethane-1,2-diamine), has been developed and synthesized. Their photophysical properties in both solution and the solid state were described. All soft salt complexes exhibit phosphorescence emission with PLQY in the solid state up to 0.36. Most of these materials displayed aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE) in water/DMSO solutions as the water ratio increased. Structure–property relationships were analyzed in relation to emission properties. The presence of the free nitrogen atoms in soft salt complexes with a C^N pyrimidine-based ligand allowed for reversible sensitivity to acidic vapors, resulting in the quenching of phosphorescence emission. Additionally, for selected soft salts, we described reversible vapochromism behaviour, making these new materials interesting for multi-detection purposes in anti-counterfeiting applications. [ABSTRACT FROM AUTHOR]

Herein we report the synthesis and structural characterization of three new europium containing coordination polymers: [Eu(terpy)(2,6-ndc)1.5]·H2O (Linus Pauling (LP) 1), [Eu(terpy)(1,4-ndc)(1,4-Hndc)] (LP-2), and [Eu(phen)(2,6-ndc)1.5]·DMF (LP-3). The title compounds were prepared hydro- or solvo-thermally and are constructed from either 1,4- or 2,6-naphthalenedicarboxylic acid (ndc) and 1,10-phenanthroline (phen) or 2,2′:6′,2′′-terpyridine (terpy) ligands. The X-ray diffraction data show LP-2 is two-dimensional while LP-1 and LP-3 are three-dimensional. Compounds LP-1 and LP-2 exhibit modest thermal stability up to 400 °C, while LP-3 was notably unstable when removed from its reaction media and prone to degradation. Despite the apparent porosity, nitrogen physisorption measurements conducted on LP-1 and LP-2 revealed lower than anticipated surface area and pore volumes of 1 m2 g−1 and 0.037 cm3 g−1 and 1 m2 g−1 and 0.015 cm3 g−1, respectively. Photoluminescence characterization of all three compounds was performed in the solid state and in all cases the results reveal bright Eu3+-based emission. The excitation spectra show the emissive properties arise from efficient ligand-to-metal resonance energy transfer. Additionally, LP-1 and LP-2 also display emission when exposed to soft X-rays, and as such show promise toward the design of scintillators. [ABSTRACT FROM AUTHOR]

We present and fully characterize a flow cell dedicated to imaging in liquid at the nanoscale. Its use as a routine sample environment for soft X-ray spectromicroscopy is demonstrated, in particular through the spectral analysis of inorganic particles in water. The care taken in delineating the fluidic pathways and the precision associated with pressure actuation ensure the efficiency of fluid renewal under the beam, which in turn guarantees a successful utilization of this microfluidic tool for in situ kinetic studies. The assembly of the described flow cell necessitates no sophisticated microfabrication and can be easily implemented in any laboratory. Furthermore, the design principles we relied on are transposable to all microscopies involving strongly absorbed radiation (e.g. X-ray, electron), as well as to all kinds of X-ray diffraction/scattering techniques. [ABSTRACT FROM AUTHOR]

Inorganic arsenic (iAs) is a well-known naturally occurring metalloid with abundant hazards to our environment, especially being a human carcinogen through arsenic-contaminated drinking water. The iAs-related contamination is usually examined by a chemical assay system or fluorescence staining technique to investigate iAs accumulation and its deleterious effects. In this work, we present a dual-modality measurement and quantitative analysis methods for the overall evaluation of various dose-dependent iAs-related cytotoxicological manifestations by the combination of the synchrotron-radiation-based scanning transmission soft X-ray microscopy (SR-STXM) and Fourier transform infrared micro-spectroscopy (SR-FTIR) techniques. The gray level co-occurrence matrix (GLCM) based machine learning was employed on SR-STXM data to quantify the cytomorphological feature changes and the dose-dependent iAs-induced feature classifications with increasing doses. The infrared spectral absorption peaks and changes of dose-dependent iAs-induced cells were obtained by the SR-FTIR technique and classified by the multi-spectral-variate principle component analysis (PCA–LDA) method, showing the separated spatial distribution of dose-dependent groups. In addition, the quantitative comparisons of trivalent and pentavalent iAs under high dose conditions (iAsIII_H & iAsV_H) demonstrated that iAsIII_H and its compounds were more toxic than iAsV_H. This method has a potential in providing the morphological and spectral characteristics evolution of the iAs-related cells or particles, revealing the actual risk of arsenic contamination and metabolism. [ABSTRACT FROM AUTHOR]

The performance of cerium-doped Y3Al5O12 (Ce3+:YAG) often depends on cerium solubility achievable in a particular preparation technology. This solubility is kinetically affected by the synthesis process which allows for Ce3+ solubility to be generally much higher in a polycrystalline material than in single crystals. This work presents Y3−xCexAl5O12 polycrystalline thin films deposited by spin-coating where cerium is substituted on yttrium sites in an interval of 3.3–25 at%. Up to a concentration of 18 at%, the samples remain single-phase, which is the highest Ce3+ doping level in YAG published so far. Absorption, excitation and emission photoluminescence spectra are presented. The photoluminescence decays of the samples containing up to 6 at% cerium are comparable in radiative lifetime to those of Ce3+:YAG single crystals having the cerium concentration limit over one order smaller. The cathodoluminescence of the samples and soft X-ray nanosecond pulse-excited decays are examined. The scintillation decays appear much faster with a 1/e decay time well below 10 ns compared to that of a Ce3+:YAG single crystal which is 140 ns. After further optimization of the microstructure and the overall scintillation yield, sol–gel prepared Ce3+:YAG thin films are promising candidates for application in fast SEM scintillation detectors, currently intensively investigated in the scintillator technology field. [ABSTRACT FROM AUTHOR]

A series of nickel dithiolene complexes Ni[S2C2(CF3)2]2 n (n = −2, −1, 0) has been investigated using Ni L- and K-edge X-ray absorption spectroscopy (XAS). The L3 centroid shifts about 0.3 eV for a change of one unit in the formal oxidation state (or 0.3 eV per oxi), corresponding to ∼33% of the shift for Ni oxides or fluorides (about 0.9 eV per oxi). The K-edge XAS edge position shifts about 0.7 eV per oxi, corresponding to ∼38% of that for Ni oxides (1.85 eV per oxi). In addition, Ni L sum rule analysis found the Ni(3d) ionicity in the frontier orbitals being 50.5%, 44.0% and 38.5% respectively (for n = −2, −1, 0), in comparison with their formal oxidation states (of Ni(II), Ni(III), and Ni(IV)). For the first time, direct and quantitative measurement of the Ni fractional oxidation state changes becomes possible for Ni dithiolene complexes, illustrating the power of L-edge XAS and L sum rule analysis in such a study. The Ni L-edge and K-edge XAS can be used in a complementary manner to better assess the oxidation states for Ni. [ABSTRACT FROM AUTHOR]

Laser-assisted microanalysis offers the advantage of determining the spatially resolved compositions in 3D. Scanning a material with a sequence of sampling laser pulses and acquiring online the related spectra allow one to map the lateral and depth distribution of elements and molecules. However, the requirement to analyse smaller and smaller length-scales is challenged by focal diffraction as well as reduction of sensitivity at the nano-scale. Electron-based microprobes still offer unmatched spatial resolution. Disruptive improvements in laser technology are however demonstrated utilizing recently self-developed extreme ultraviolet or soft X-ray lasers. Firstly, a significant enhancement of the resolution is accomplished thanks to a much shorter wavelength, with respect to state-of-the-art commercial lasers. Furthermore, as the most innovative aspect, the sampling efficiency is enhanced using "ionizing radiation", i.e. directly activating the target material. The high photon-energy (20–100 eV) makes the sampling process essentially single-photon, whatever bond or ionization energy. Furthermore, the analytical setup is simplified to a sampling source and detector, i.e. without the need for a secondary ionization or excitation source as in some state-of-the-art analytical systems. In this review, fundamental aspects of X-ray laser desorption and ablation are discussed, and a survey of the available literature is presented. The main objective is to convince the reader that desorption or ablation in this spectral domain is a significantly cleaner sampling process, with large potential, still requiring investigation for a complete fundamental understanding. Applications of laser microanalysis are thus entering the nano-scale era, which shrinks the gap with electron-based microprobes. [ABSTRACT FROM AUTHOR]