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Ge1−xSnx and Si1−x−yGeySnx alloys are promising materials for future opto- and nanoelectronics applications. These alloys enable effective bandgap engineering, broad adjustability of their lattice parameter, exhibit much higher carrier mobility than pure Si, and are compatible with the complementary metal-oxide-semiconductor technology. Unfortunately, the equilibrium solid solubility of Sn in Si1−xGex is less than 1% and the pseudomorphic growth of Si1−x−yGeySnx on Ge or Si can cause in-plane compressive strain in the grown layer, degrading the superior properties of these alloys. Therefore, post-growth strain engineering by ultrafast non-equilibrium thermal treatments like pulse laser annealing (PLA) is needed to improve the layer quality. In this article, Ge0.94Sn0.06 and Si0.14Ge0.8Sn0.06 thin films grown on silicon-on-insulator substrates by molecular beam epitaxy were post-growth thermally treated by PLA. The material is analyzed before and after the thermal treatments by transmission electron microscopy, x-ray diffraction (XRD), Rutherford backscattering spectrometry, secondary ion mass spectrometry, and Hall-effect measurements. It is shown that after annealing, the material is single-crystalline with improved crystallinity than the as-grown layer. This is reflected in a significantly increased XRD reflection intensity, well-ordered atomic pillars, and increased active carrier concentrations up to 4 × 1019 cm−3. [ABSTRACT FROM AUTHOR]

Scanning spreading resistance microscopy (SSRM) measurements were performed on GaAs thick films grown by hydride vapor phase epitaxy technology under different growth conditions to evaluate their carrier concentrations. For this purpose, a calibration curve was established based on a multilayer staircase structure grown by molecular beam epitaxy. The dopant calibration range measured by secondary ion mass spectrometry is from 5 × 1016 to 1019 cm−3. An abnormal phenomenon in the calibration process was explained by taking into account the parasitic parallel resistance of the calibration samples. Finally, the calibration curve was used to quantitatively analyze the carriers inside the Zn doping p-type GaAs film from 4 × 1016 to 1018 cm−3 range. We demonstrate here the applicability of SSRM to the in-depth analysis of thick epilayers, providing new inputs for the control of thick film technologies. [ABSTRACT FROM AUTHOR]

AlxGa1−xN epilayers are used as the basis of ultraviolet LEDs and detectors. The trap states produced by defects and impurities can play a key role in the device performance. In this work, conventional deep-level transient spectroscopy, photoluminescence (PL), and secondary ion mass spectrometry have been used to characterize a deep-level trap termed as E3 in dilute AlxGa1−xN (x < 0.063) epilayers grown by metal-organic vapor phase epitaxy (MOVPE) on highly conductive ammono-GaN substrates. The AlxGa1−xN epilayers were doped with silicon to about 3 × 1016 cm−3. The electrical and the optical measurements were conducted on Ni/Au Schottky barrier diodes and virgin samples, respectively. First, we observed a general trend that the E3 (FeGa) electron trap concentration significantly changes along the wafers in AlxGa1−xN layers that is fully consistent with previously reported results for GaN materials grown by the MOVPE technique. Second, we report that the activation energies for electron emission for the E1 and E3 traps in dilute AlxGa1−xN exhibit linear variations with Al content. Moreover, low-temperature PL results show a proportional relation between the intensity of the line with its maximum at 1.299 eV and concentration of residual Fe impurity. Finally, we discuss how the presence of defects resulting from Fe contamination may result in degradation of AlxGa1−xN-based devices. [ABSTRACT FROM AUTHOR]

Since the 1940s, it has been known that diffusion in crystalline solids occurs due to lattice defects. The diffusion of defects can have a great impact on the processing and heat treatment of materials as the microstructural changes caused by diffusion can influence the material qualities and properties. It is, therefore, vital to be able to control the diffusion. This implies that we need a deep understanding of the interactions between impurities, matrix atoms, and intrinsic defects. The role of density functional theory (DFT) calculations in solid-state diffusion studies has become considerable. The main parameters to obtain in defect diffusion studies with DFT are formation energies, binding energies, and migration barriers. In particular, the utilization of the nudged elastic band and the dimer methods has improved the accuracy of these parameters. In systematic diffusion studies, the combination of experimentally obtained results and theoretical predictions can reveal information about the atomic diffusion processes. The combination of the theoretical predictions and the experimental results gives a unique opportunity to compare parameters found from the different methods and gain knowledge about atomic migration. In this Perspective paper, we present case studies on defect diffusion in wide bandgap semiconductors. The case studies cover examples from the three diffusion models: free diffusion, trap-limited diffusion, and reaction diffusion. We focus on the role of DFT in these studies combined with results obtained with the experimental techniques secondary ion mass spectrometry and deep-level transient spectroscopy combined with diffusion simulations. [ABSTRACT FROM AUTHOR]

The concentration of vacancies and impurities in semiconductors plays a crucial role in determining their electrical, optical, and thermal properties. This study aims to clarify the nature of the interaction between positrons and ionized p-type impurities, emphasizing the similarities they share with the interaction between holes and this type of impurity. An overall strategy for investigating defects in semiconductor crystals that exhibit a combination of vacancies and p-type impurities is presented. By using positron annihilation spectroscopy, in particular, Doppler broadening of the annihilation radiation, we quantify the concentration of vacancies in epitaxial Si crystals grown by low-energy plasma-enhanced chemical vapor deposition. The vacancy number densities that we find are (1.2 ± 1.0) × 1017 cm−3 and (3.2 ± 1.5) × 1020 cm−3 for growth rates of 0.27 and 4.9 nm/s, respectively. Subsequent extended annealing of the Si samples effectively reduces the vacancy density below the sensitivity threshold of the positron technique. Secondary ion mass spectrometry indicates that the boron doping remains unaffected during the annealing treatment intended for vacancy removal. This study provides valuable insights into the intricate interplay between vacancies and ionized impurities with positrons in semiconductor crystals. The obtained results contribute to advance the control and understanding of material properties in heterostructures by emphasizing the significance of managing vacancy and dopant concentrations. [ABSTRACT FROM AUTHOR]

We performed Ge doping of α-Ga2O3 thin films grown on m-plane sapphire substrates using mist chemical vapor deposition. Although the typical growth rate was high at 4 μm/h, the resultant α-Ga2O3 thin films exhibited high crystallinity. We controlled the carrier density in the range of 8.2 × 1016–1.6 × 1019 cm−3 using bis[2-carboxyethylgermanium(IV)]sesquioxide as the Ge source. The highest mobility achieved was 66 cm2 V−1 s−1 at a carrier concentration of 6.3 × 1017 cm−3. Through secondary ion mass spectrometry analysis, a linear relationship between the Ge concentration in the α-Ga2O3 thin films and the molar ratio of Ge to Ga in the source solution was established. The quasi-vertical Schottky barrier diode fabricated using the Ge-doped α-Ga2O3 thin films exhibited an on-resistance of 7.6 mΩ cm2 and a rectification ratio of 1010. These results highlight the good performance of the fabricated device and the significant potential of Ge-doped α-Ga2O3 for power-device applications. [ABSTRACT FROM AUTHOR]

We generalize a native Nb 2 O 5 dissolution model [G. Ciovati, Appl. Phys. Lett. 89, 022507 (2006)] to sequential overlayer dissolutions, multilayer dissolution, and realistic temperature profiles, which may be applicable to other materials. The model is applied to secondary ion mass spectrometry depth profile measurements for varying temperature profiles and two-step oxide dissolution in Nb and found to agree well. In the context of the Meissner screening response due to impurity profiles on the length scale of the London penetration depth, the shallow diffusion of O impurities results in a substantial decrease in the peak supercurrent density near the surface. In this framework, oxide dissolution and oxygen diffusion can account for a rise in peak supportable magnetic field in SRF cavities with baking time and a suppression after the optimal baking time is reached, in good agreement with peak-field baking temperatures and times as well as recent quench field measurements. [ABSTRACT FROM AUTHOR]

Using the novel process of hot N+-ion implantation at 800 °C into Si quantum dots (Si-QDs) with approximately 3.2 nm fabricated by hot Si+-ion implantation into an SiO2 layer and post-Ar annealing, we experimentally demonstrated that the photoluminescence intensity (IPL) of the Si-QDs increased with increasing N+-ion dose (D N + ). Post-N2 high-temperature annealing without hot N+-ion implantation, as a reference process, also increased the IPL of Si-QDs, because N atoms trapped within Si-QDs, which was evaluated by secondary ion mass spectrometry, terminate the dangling bonds within Si-QDs and at the Si/SiO2 interface. Additionally, the IPL of Si-QDs showed the maximum value at the optimal D N + of 5 × 1015 cm−2, which was 1.4-fold higher than that observed without hot N+-ion implantation. With a short post-annealing time (<60 min), the increase in IPL owing to N+-ion implantation was considerably larger than that caused by N2 annealing, which is likely due to the efficiency of the termination of the dangling bonds of the Si-QDs by the N+-ions. This is an advantage of the hot N+-ion implantation technique. Forming gas annealing after furnace annealing also induced a larger IPL than that observed before forming gas annealing. However, the maximum IPL observed after forming gas annealing was completely independent of the conditions of furnace annealing and D N + . This suggests that the perfect termination of the dangling bonds of the Si-QDs may be realized via forming gas annealing after furnace annealing. [ABSTRACT FROM AUTHOR]

This study investigates the effects of kinetic energy and projectile size on particle emission from a phenylalanine overlayer adsorbed on a graphene bilayer during argon projectile bombardment. Projectiles of various sizes (1–1000 atoms) and kinetic energies (0.5–40 keV) are used to study their impact on the ejection efficiency, mass distribution, and kinetic and angular spectra of the emitted substances. Particle ejection mechanisms are discussed in scenarios with and without sample perforation. Additionally, this study investigated the potential use of graphene in secondary ion mass spectrometry or neutral secondary mass spectrometry analyses. [ABSTRACT FROM AUTHOR]

High quality, uni-polar, epitaxial AlN with minimum oxygen content promises excellent surface acoustic wave and bulk acoustic wave resonator characteristics such as high electromechanical coupling coefficient and power handling capabilities, which is particularly useful for RF filter applications. By systematically varying the growth temperature, the study investigates its impact on the oxygen levels, defect states, and crystallographic texture of the AlN thin films using a combination of atomic force microscopy, X-ray diffraction, time-of-flight secondary ion mass spectrometry, spectroscopic ellipsometry, scanning transmission electron microscopy, as well as room temperature and temperature dependent I–V measurements. The research demonstrates that the films grown at a temperature of 700 ° C exhibit the most favorable results. These films exhibit the lowest oxygen levels, possess epitaxial growth, and display the highest crystalline quality (XRD AlN 0002 ω − FWHM = 1.3 °). Additionally, these films demonstrate a significant reduction in sub-bandgap absorption. By comparing the cathode current measured during deposition, we suggest that the presence of an impurity layer formed during idle time between depositions as a possible source of oxygen in the sputter chamber. In addition, the study presents a possible model to explain the mixed polarity observed in AlN and proposes various ways to achieve uni-polar AlN on silicon substrates. [ABSTRACT FROM AUTHOR]

In this study, we investigate the diffusion of Si donors in AlN. Amorphous S i 1 − x N x sputtered on the surface of bulk AlN with low dislocation density is used as a Si source. The diffusion experiments are conducted through isochronal and isothermal annealing in a protective N2 atmosphere at temperatures between 1500 and 1700 °C. The Si depth profiles measured by secondary ion mass spectrometry exhibit a convex box-like shape with a steep diffusion front. These concentration profiles are best described with a diffusion coefficient that depends on the square of local Si concentration. From the characteristic box-shaped Si profiles, we conclude that diffusion of Si in AlN is mediated by singly negatively charged dopant–vacancy pairs S i Al V Al −. The strong concentration dependence of Si diffusion is due to the electric field associated with the incorporation of Si donors ( Si Al + 1 ) on substitutional Al lattice sites and reflects that Si is fully electrically active at diffusion temperature. The experimentally obtained extrinsic Si diffusion coefficient is reduced to intrinsic doping conditions. The temperature dependence of Si diffusion for intrinsic conditions is described by an activation enthalpy of (10.34 ± 0.32) eV and a pre-exponential factor of 235 − 203 + 1485 c m 2 s − 1 . The migration enthalpy of the donor–vacancy pair S i Al V Al − is estimated to be around 3.5 eV. This estimation is based on the activation enthalpy of the transport capacity of S i Al V Al − and theoretical results concerning the formation energy of negatively charged vacancies on Al-sites in AlN. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD) polymerization is a commonly used approach in surface chemistry, providing a substrate‐independent platform for bioactive surface functionalization strategies. This work investigates the Arbuzov reaction of halogenated polymer coatings readily available via CVD polymerization, using poly(4‐chloro‐para‐xylylene) (Parylene C) as a model substance. Postpolymerization modification of these coatings via catalyst‐free and UV‐induced Arbuzov reaction using phosphites results in phosphonate‐functionalized polymers. The combination of infrared reflection‐absorption spectroscopy (IRRAS), X‐ray photoelectron spectroscopy (XPS), and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) provides detailed insights into the reaction progress. Time‐dependent studies suggest that the non‐polar phosphites penetrate deep into the CVD films and react with the polymer film. In addition, ToF‐SIMS, scanning electron microscopy (SEM), and atomic force microscopy (AFM) confirm spatial control of the reaction, resulting in localized chemical and topographical surface modification, recognizable by changes in interference color, fluorescence, and wettability. Preliminary 3D fluorescence spectroscopy investigations indicate tunable near‐infrared emission of these polymer films. This work is the first step toward generating multifunctional polymer coatings based on chemically modifiable, CVD polymers with potential applications in biomaterials, sensors, or optoelectronics. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) benefits from high process temperatures when the substrate is not temperature-sensitive because the films deposited at higher temperatures exhibit better electrical properties. In this study, we investigated the ALD process of silicon oxide films by alternating injections of tris(dimethylamino)silane (tris-DMAS) and O 3 /O 2 at temperatures ranging from 400 to 700 °C. The saturation dose of tris-DMAS was 1.5 × 106 L at 400 °C. Self-limiting growth with a growth rate of approximately 0.9 Å/cycle was observed up to 600 °C, allowing excellent step coverage. However, at 700 °C, the growth rate increased significantly to 4.6 Å/cycle, carbon and nitrogen impurities were detected by secondary ion mass spectrometry, and step coverage was poor, supporting the thermal decomposition of tris-DMAS at this temperature. Therefore, the optimum temperature for ALD SiO 2 using tris-DMAS is 600 °C for application as an insulating film on high aspect ratio patterns. At this temperature, the leakage current density was 0.58 nA/cm2, and the oxide-trapped charge density was 4.0 × 1010 cm−2. [ABSTRACT FROM AUTHOR]

Understanding crystal characteristics down to the atomistic level increasingly emerges as a crucial insight for creating solid state platforms for qubits with reproducible and homogeneous properties. Here, isotope concentration depth profiles in a SiGe/28Si/SiGe heterostructure are analyzed with atom probe tomography (APT) and time‐of‐flight secondary‐ion mass spectrometry down to their respective limits of isotope concentrations and depth resolution. Spin‐echo dephasing times T2echo=128μs$T_2^\mathbf {echo}=128 \,\umu\mathrm{s}$ and valley energy splittings EVS around 200μeV$200 \,\umu\mathrm{e\mathrm{V}}$ have been observed for single spin qubits in this quantum well (QW) heterostructure, pointing toward the suppression of qubit decoherence through hyperfine interaction with crystal host nuclear spins or via scattering between valley states. The concentration of nuclear spin‐carrying 29Si is 50 ± 20ppm in the 28Si QW. The resolution limits of APT allow to uncover that both the SiGe/28Si and the 28Si/SiGe interfaces of the QW are shaped by epitaxial growth front segregation signatures on a few monolayer scale. A subsequent thermal treatment, representative of the thermal budget experienced by the heterostructure during qubit device processing, broadens the top SiGe/28Si QW interface by about two monolayers, while the width of the bottom 28Si/SiGe interface remains unchanged. Using a tight‐binding model including SiGe alloy disorder, these experimental results suggest that the combination of the slightly thermally broadened top interface and of a minimal Ge concentration of 0.3$0.3$% in the QW, resulting from segregation, is instrumental for the observed large EVS=200μeV$E_\mathrm{VS}=200 \,\umu\mathrm{e\mathrm{V}}$. Minimal Ge additions <1%, which get more likely in thin QWs, will hence support high EVS without compromising coherence times. At the same time, taking thermal treatments during device processing as well as the occurrence of crystal growth characteristics into account seems important for the design of reproducible qubit properties. [ABSTRACT FROM AUTHOR]

Although a few studies report that tuning Ti/Al thicknesses at a fixed ratio can further improve the Ohmic contact to AlGaN/GaN heterostructure, systematic physical mechanisms have not been reported. In this work, after determining the optimal Ti/Al ratio of 1/4, two metal stacks with varying Ti/Al thicknesses and fixed Ni/TiN thicknesses are deposited to investigate how tuning Ti/Al thicknesses at an optimized ratio enhances the Ohmic contact performance. At the optimal annealing condition (950 °C, 45 s) of samples with Ti/Al thicknesses of 20/80 nm, samples with Ti/Al thicknesses of 35/140 nm exhibit a reduction of 48% in contact resistance and 70% in specific contact resistivity (ρc). By correlating the results from ρc–T measurements, time‐of‐flight secondary ion mass spectrometry, and high‐resolution X‐ray diffraction, it has been determined that this method effectively enables N‐vacancies doping into the heterostructure, thereby increasing the carrier concentration and reducing both the height and width of the interfacial potential barrier, achieving a more efficient carrier transport. By avoiding the use of Au with high solubility and ductility, this approach significantly improves contact performance without adversely affecting the electrode surface morphology, demonstrating good adaptability for optimizing Au‐free Ohmic contacts. [ABSTRACT FROM AUTHOR]

The primary component of the lipid barrier on human hair, which is essential for defense against aging and environmental stresses, is 18-methyleicosanoic acid (18-MEA), which provides hydrophobic properties and protective benefits. Since 18-MEA cannot be regenerated once damaged, developing technology that can permanently bind alternative materials to hair is critical. Once 18-MEA was removed from hair via X-ray photoelectron spectroscopy (XPS), pentaerythritol tetraisoosterate (PTIS) was hydrolyzed and observed via gas chromatography/mass spectrometry (GC/MS) to confirm that it mimicked 18-MEA, and 16-methylheptadecanoic acid (16-MHA) was obtained at pH 4 or lower. 16-MHA was bioconjugated to damaged hair from which 18-MEA was removed via a carbodiimide reaction using polycarbodiimide. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) confirmed that 16-MHA remained on the surface of the bioconjugated hair even after washing. Observation of the endothermic reaction of moisture in hair via a differential scanning calorimetry (DSC) and evaluation of the moisture content confirmed that the physical properties of hair enriched with 16-MHA were similar to those of virgin hair. This biomimetic approach has been shown to restore both external structural integrity and internal moisture homeostasis. [ABSTRACT FROM AUTHOR]

Cancer has become one of the leading causes of death, with approximately ten million people worldwide dying from cancer each year. In most cases, cancer spreads to remote organs and develops a resistance to therapy. To reduce the deadly impact of cancer, novel targets for markers for early detection are necessary. Given the notable influence of rapid chemical turnover on isotope effects, the heightened turnover rate of cholesterol in cancer offers a promising way for investigation. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) offers a valuable tool of tracking cholesterol dynamics. Consequently, we employed ToF-SIMS to assess cholesterol alterations, aiming to uncover potential diagnostic vulnerabilities stemming from heightened cholesterol synthesis. Our study explored the chemical profile of cholesterol influenced by cancer cell metabolism using mammary glands from mice, both with and without cancer. Results revealed a significant increase in the fractional abundance of fragment cholesterol peaks (C27H45+) in cancerous tissues, indicating dysregulated cholesterol metabolism within cancer cells. This suggests potential structural weaknesses or incomplete synthesis. Further investigation into carbon isotope incorporation suggests that the isotopic patterns might be due to the integration of heavier carbon isotopes, although these patterns could be affected by other isotopic influences. Nevertheless, understanding isotope effect of cholesterol profiles have the potential to advance our understanding of cancer biology and improve diagnostic approaches. [ABSTRACT FROM AUTHOR]

Few aerobic hyperthermophilic microorganisms degrade polysaccharides. Here, we describe the genome-enabled enrichment and optical tweezer-based isolation of an aerobic polysaccharide-degrading hyperthermophile, Fervidibacter sacchari, previously ascribed to candidate phylum Fervidibacteria. F. sacchari uses polysaccharides and monosaccharides for growth at 65–87.5 °C and expresses 191 carbohydrate-active enzymes (CAZymes) according to RNA-Seq and proteomics, including 31 with unusual glycoside hydrolase domains (GH109, GH177, GH179). Fluorescence in-situ hybridization and nanoscale secondary ion mass spectrometry confirmed rapid assimilation of 13C-starch in spring sediments. Purified GHs were optimally active at 80–100 °C on ten different polysaccharides. Finally, we propose reassigning Fervidibacteria as a class within phylum Armatimonadota, along with 18 other species, and show that a high number and diversity of CAZymes is a hallmark of the phylum, in both aerobic and anaerobic lineages. Our study establishes Fervidibacteria as hyperthermophilic polysaccharide degraders in terrestrial geothermal springs and suggests a broad role for Armatimonadota in polysaccharide catabolism. Few aerobic hyperthermophilic microorganisms are known to degrade polysaccharides. Here, Nou et al. use genomic information to enrich and optical tweezers to isolate an aerobic hyperthermophilic bacterium that can grow at 65–87.5 °C using polysaccharides as sole carbon sources. [ABSTRACT FROM AUTHOR]

Doping silicon wafers without using highly toxic or corrosive chemical substances has become a critical issue for semiconductor device manufacturing. In this work, ultra‐thin films of hydroxyapatite (Ca5(PO4)3OH) are prepared by tethering by aggregation and growth (T‐BAG), and further processed by spike annealing. Via in situ infrared (IR), the decomposition of hydroxyapatite and intermixing with the native silicon oxide is observed already at temperatures as low as 200 °C. Phosphate transport through the native silicon oxide is driven by a phase transformation into a more stable thermal oxide. At 700 °C, diffusion of phosphorus into the sub‐surface region of oxide‐free silicon is observed. In situ IR combined with electrical impedance spectroscopy (EIS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and X‐ray photoelectron spectroscopy (XPS) measurements allows to conclude that the phosphorus is: i) transported through the silicon oxide barrier, ii)) diffused inside the oxide‐free silicon, and iii) finally modified the electrical activity of the silicon wafer. To further explain the experimental findings, density‐functional theory (DFT) is used to demonstrate the extent of the effect of phosphorus doping on the electronic nature of silicon surfaces, showing that even small amounts of doping can have a measurable effect on the electrical performance of semiconductor wafers. [ABSTRACT FROM AUTHOR]

The Yanliao Biota from northern China is one of the most famous Mesozoic terrestrial lagerstätten in the world, with well-preserved fossil records in the Jurassic volcanic-sedimentary Ningcheng and Jianchang basins. However, the temporal evolution of the Yanliao Biota remains controversial, mainly due to the confusing stratigraphic framework and the unclear age of fossiliferous deposits in the Ningcheng basin. To address this issue, we carried out detailed field investigations and secondary ion mass spectrometry (SIMS) U-Pb age dating of zircons on fossiliferous and related strata in the southern part of the Ningcheng basin. The Jurassic infill of this area is composed of, in ascending order, fossil-bearing tuffaceous clastic rocks (unit 1), andesite and pyroclastic rocks (unit 2), fossil-bearing clastic rocks interlayered with minor volcanic rocks (unit 3), and andesite and pyroclastic rocks (unit 4). Integration of stratigraphic and geochronological data indicates that the Yanliao Biota in the Ningcheng basin appeared no later than ca. 163 Ma and lasted until ca. 156 Ma. A comparison with other analogous basins in northern China (e.g., the Luanping, Jianchang, and Beipiao basins) leads to the conclusion that the Yanliao Biota evolved in two phases and lasted for more than 11 m.y.: the first phase from ca. 167 Ma to ca. 163 Ma in the middle Bathonian to middle Callovian, followed by the second phase between ca. 161 Ma and ca. 156 Ma in the lower and middle Oxfordian. [ABSTRACT FROM AUTHOR]

The oxidation of hydrocarbons, including methane, is part of interrelated hydrogeochemical reactions affecting the carbon budget in Earth's crust. To investigate these processes in deep siliciclastic strata, we analyzed core samples from Lower Triassic red beds in the Mahu Sag (Junggar Basin, northwest China) by coupling petrological observations with high-resolution in situ secondary ion mass spectroscopy stable carbon and oxygen isotope analyses and clumped isotopes (47) of authigenic calcite. The strata contain variable oil and gas content as well as abundant high-valence Fe and/ or Mn oxides. Three sequential generations of cement occur, which are characterized as (1) non-luminescent, early diagenetic calcite (MnO <0.3%, d13CVPDB [Vienna Peedee belemnite] = -5.6‰ to -4.1‰); (2) bright-orange luminescent late-stage I calcite (0.75%-5.23% MnO, d13C = -51.4‰ to -25.8‰); and (3) dull-orange late-stage II calcite (4.10%-12.93% MnO, d13C = -91.4‰ to -30.9‰). Clumped isotopic thermometry reveals that the calcite precipitation temperature increases successively from <40 °C, to 81-107 °C, to finally 107-132 °C, corresponding to three precipitation time periods: before the Late Triassic, from the Early Jurassic to the Early Cretaceous, and from the Early Cretaceous to the present, respectively. d13C values of -55.7‰ to -25.8‰ indicate that late-stage I calcite is the final product of oxidation of both methane and C2+ hydrocarbons, whereas d13C values as low as -91‰ indicate that late-stage II calcite is mainly derived from the thermochemical oxidation of methane (d13C = -46.8‰ to -39.3‰) induced by high-valence Mn and/ or Fe oxides. For late-stage I calcite, hydrocarbon oxidation was most likely promoted by high temperatures, although microbial oxidation cannot be completely ruled out. The higher precipitation temperature of latestage II calcite demonstrates that the oxidation of methane requires higher activation energies than oxidation of C2+ hydrocarbons. We provide reliable geochemical evidence for thermally induced sequential oxidation of hydrocarbons within deep siliciclastic strata. [ABSTRACT FROM AUTHOR]

Hierarchically porous monolithic silica shows promise as a carrier material for immobilized organocatalysts. Conventional analysis usually includes physisorption, infrared spectroscopy and elemental analysis, among others, to elucidate the pore space and degree of functionalization of the material. However, these methods do not yield information about the spatial distribution of the organic species inside the monolithic reactor. In this work, time‐of‐flight secondary ion mass spectrometry has been applied to characterize the surface of organically functionalized silica monoliths. Cross sections of a silica monolith functionalized with 4‐dimethylaminopyridine were analyzed and the results were compared with physisorption and elemental analysis experiments of the same material. This way, insight into the radial distribution of the catalyst could be achieved, which might assist in interpreting the performance of such reactors in heterogeneous flow catalysis. [ABSTRACT FROM AUTHOR]

The advancement of solid-state hydrogen storage materials is critical for the realization of a sustainable hydrogen economy. This comprehensive review elucidates the state-of-the-art characterization techniques employed in solid-state hydrogen storage research, emphasizing their principles, advantages, limitations, and synergistic applications. We critically analyze conventional methods such as the Sieverts technique, gravimetric analysis, and secondary ion mass spectrometry (SIMS), alongside composite and structure approaches including Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). This review highlights the crucial role of in situ and operando characterization in unraveling the complex mechanisms of hydrogen sorption and desorption. We address the challenges associated with characterizing metal-based solid-state hydrogen storage materials discussing innovative strategies to overcome these obstacles. Furthermore, we explore the integration of advanced computational modeling and data-driven approaches with experimental techniques to enhance our understanding of hydrogen–material interactions at the atomic and molecular levels. This paper also provides a critical assessment of the practical considerations in characterization, including equipment accessibility, sample preparation protocols, and cost-effectiveness. By synthesizing recent advancements and identifying key research directions, this review aims to guide future efforts in the development and optimization of high-performance solid-state hydrogen storage materials, ultimately contributing to the broader goal of sustainable energy systems. [ABSTRACT FROM AUTHOR]

The application of hydrogen flooding was recently shown to be a simple and effective approach for improved layer differentiation and interface determination during secondary ion mass spectrometry (SIMS) depth profiling of thin films, as well as an approach with potential in the field of quantitative SIMS analyses. To study the effects of hydrogen further, flooding of H2 molecules was compared to reactions with atomic H on samples of pure metals and their alloys. H2 was introduced into the analytical chamber via a capillary, which was heated to approximately 2200 K to achieve dissociation. Dissociation of H2 up to 30% resulted in a significant increase in the intensity of the metal hydride cluster secondary ions originating from the metallic samples. Comparison of the time scales of possible processes provided insight into the mechanism of hydride cluster secondary ion formation. Cluster ions presumably form during the recombination of the atoms and molecules from the sample and atoms and molecules adsorbed from the gas. This process occurs on the surface or just above it during the sputtering process. These findings coincide with those of previous mechanistic and computational studies. [ABSTRACT FROM AUTHOR]

This study employs secondary ion mass spectrometry (SIMS) to investigate the diffusion behavior of hydrogen and carbon in a CdxZn1−xO:Eu multilayer at different annealing temperatures (500–900 °C). The SIMS results reveal a significant out-diffusion of these elements toward the surface and diffusion to the interface region. The diffusion flow rates are asymmetric and favor the interface direction. The depth profiles of diffused elements are fitted using the forward timecentered space (FTCS) iteration method. The activation energies are determined to be 0.35 ± 0.06 eV for hydrogen and 0.33 ± 0.09 eV for carbon, suggesting an interstitial mechanism in CdxZn1−xO. The results indicate that increasing the annealing temperatures leads to a significant decrease in impurity concentrations. [ABSTRACT FROM AUTHOR]

Most melanomas progress from radial to vertical growth phase before spreading locoregionally and distally. Much is still unknown about the metabolic changes in the tumor cells and their microenvironment during this metastatic progression. We aimed to gain new insight into the molecular characteristics of melanoma in regard to spatial lipidomics to deliver new knowledge regarding tumor metastatic progression. We included 10 fresh tumor samples from 10 patients including two in situ melanomas, two invasive primary melanomas, and six metastatic melanomas (four in‐transit metastases and two distant metastases). In addition, we analyzed four healthy skin controls from the same patients. Time‐of‐flight imaging secondary ion mass spectrometry (ToF‐SIMS) enabled detailed spatial‐lipidomics that could be directly correlated with conventional histopathological analysis of consecutive H&E‐stained tissue sections. Significant differences in the lipid profiles were found in primary compared to metastatic melanomas, notably an increase in phosphatidylethanolamine lipids relative to phosphatidylinositol lipids and an increase in GM3 gangliosides in the metastatic samples. Furthermore, analysis of the data from in transit versus distant metastases samples highlighted that specific phospholipids, and a difference in the long versus shorter chain GM3 gangliosides, discriminated the metastatic routes. Further studies are warranted to verify these preliminary findings. Lipidomic changes could serve as a novel biomarker for tumor progression and even serve as a target for novel treatments. Furthermore, analyzing the lipid profiles could help to differentiate between primary and metastatic melanomas in challenging cases. [ABSTRACT FROM AUTHOR]

Plasma etching is a crucial step in semiconductor manufacturing. High cleanliness and wafer‐to‐wafer reproducibility in the etching chamber are essential in order to successfully achieve nanometer‐sized integrated functions on the wafer. The trend toward the application of more aggressive plasma compositions leads to higher demands on the plasma resistance of the materials used in the etching chamber. Due to its excellent etch resistance, yttrium aluminum garnet Y3Al5O12 (YAG) is starting to replace established materials like SiO2 or Al2O3 in this kind of application. In this study, reactive spark plasma sintering (SPS) was used to manufacture highly dense YAG ceramics from the respective oxides. In addition, yttrium was replaced with heavier lanthanoids (Er, Lu), intending to investigate the role of the A‐site cation in the garnet type structure on the plasma erosion behavior. The produced materials were exposed to fluorine‐based etching plasmas mimicking the conditions in the semiconductor manufacturing apparatus and the erosion behavior was characterized by atomic force microscopy (AFM), secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), and profilometry. The induced chemical gradient in the samples is limited to a few nanometers below the surface, which makes its characterization challenging. For advanced analysis, we developed a correlative characterization method combining SIMS and scanning TEM (STEM)–energy‐dispersive spectroscopy (EDS) enabling us to examine the structural and chemical changes in the reaction layer locally resolved. In the case of lanthanoid aluminates, an altered reaction layer and reduced fluorine penetration compared to YAG were found. However, a correlation between the characteristics of the induced chemical gradient and the determined physical erosion rates was not evident. [ABSTRACT FROM AUTHOR]

A multifaceted characterization approach is proposed, aiming to establish a link between nanoscale electrical properties and macroscale device characteristics. Current–voltage (I–V) measurements are combined with admittance spectroscopy (AS) and deep‐level transient spectroscopy (DLTS) for the analysis of charge‐related performance losses with time‐of‐flight secondary‐ion mass spectrometry to complete the understanding of ionic motion in the device. This is applied to the study of surface treatment in perovskite solar cells, which implements several strategies to improve band alignment, perovskite grain growth, and chemical passivation. An increase of both open‐circuit voltage (Voc) and fill factor of respectively 90 mV and 11% is shown after surface treatment, with an absolute efficiency increase of 4%. AS measurements, coupled with a lumped elements model, rule out the impact of transport layers as the origin of the performance improvement, rather pointing toward a reduction in ionic resistance in the perovskite bulk. Analysis of the DLTS response yields an activation energy of 0.41 eV, which is likely related to the same ionic mechanism discovered with AS. Finally, both of these techniques enable to show that the surface treatment main contribution is to reduce ion‐related recombination of charge carriers. [ABSTRACT FROM AUTHOR]

This work presents the advancement of lead‐free tin perovskite photodiodes in terms of their photodetection and air stability by incorporating germanium (Ge) and ethylenediamine (EDA) to formamidinium tin iodide (FASnI3). EDA0.01FA0.98SnI3:Ge‐based photodiodes demonstrate a significantly improved specific detectivity (1.6 × 1012 Jones at −0.1 V), cut‐off frequency (6.6 × 105 Hz), response speed (0.53 µs), and signal‐to‐noise ratio (45 dB) compared with control devices. The superior performance is attributed to the stronger Ge─I bond, the passivation of Sn2+ and I– vacancies by smaller Ge2+ ions, the promotion of a fully 3D perovskite structure, the elevation of the conduction band energy level, and the formation of a protective GeO layer. Various film analyses, including X‐ray photoelectron spectroscopy, UV photoelectron spectroscopy, density functional theory, as well as device testing using time‐of‐flight secondary ion mass spectrometry and voltage‐dependent admittance, support and explain the mechanisms behind the enhancements. Ge‐ and EDA‐incorporated photodiodes exhibit excellent air stability, as evidenced by the time‐dependent ultraviolet visible spectra and the considerably high certified power conversion efficiency without encapsulation in air, demonstrating their potential for practical applications. The obtained photodetection performance is highest among the published lead‐free tin‐based perovskite photodetectors, presenting a monumental progress from the previous report of the same group. [ABSTRACT FROM AUTHOR]

High-quality aluminum nitride (AlN) films on silicon substrates are crucial for various applications due to their inherent properties as wide-bandgap semiconductors, cost-effectiveness, and compatibility with silicon-based circuits. Nonetheless, producing high-quality and crack-free AlN on silicon presents significant challenges due to the stress caused by lattice and thermal expansion mismatches. This study introduces a method to mitigate these challenges by incorporating a boron precursor during the metalorganic chemical vapor deposition process to form a BAlN buffer layer. Analytical techniques, such as secondary ion mass spectrometry, atomic force microscopy imaging, XRD rocking curves, reciprocal space map, and Raman spectroscopy, indicate that the BAlN buffer layer promotes the enlargement of seed crystal size, which effectively delays AlN coalescence, mitigates accumulated tensile stress, and enhances the overall crystal quality. Employing this technique has produced a 520 nm thick, crack-free AlN film on silicon (111) with high crystal quality, achieving full width at half maximum values of only 0.2° and 0.3° for XRC (002) and (102), respectively. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, the etching characteristics of InGaZnO4 (IGZO) thin films were systemically investigated in inductively coupled CH4/Ar plasmas with various gas ratios, bias voltages, and surface temperatures. The ion flux in the CH4/Ar plasmas was analyzed using bias power and voltage, whereas the relative densities of CH and H radicals were quantified through optical actinometry. The change in CH3 radical density was also estimated based on plasma kinetics analysis. The correlations between the plasma properties and IGZO etch rate were investigated. In CH4/Ar plasmas with CH4 ratios below 80%, the IGZO etch rate increases with a higher CH4 proportion, aligning with the ascending trend of CH3 radical density, which suggests that CH3 radical density acts as a limiting factor (radical‐limited regime). However, the IGZO etch rate decreases when the CH4 ratio exceeds 80%, corresponding to the reduction in ion flux, which indicates that ion flux becomes a limiting factor in this ion‐limited regime. The IGZO etch rate shows a linear relationship with bias voltage and follows the Arrhenius equation with varying surface temperature in plasmas without bias voltage. A spontaneous etch model was proposed based on these relationships. In this model, the IGZO etch rate depends on CH3 radical density and IGZO surface reactivity, where ion bombardment contributes more significantly to surface reactivity than high surface temperature. IGZO thin film was deposited on SiO2 during the fabrication of a 3D stacked ferroelectric field‐effect transistor (FeFET) memory device. The interaction between IGZO and SiO2 during CH4/Ar plasma processing was investigated using time‐of‐flight secondary ion mass spectrometry. The efficacy of removing IGZO atoms that had diffused into the SiO2 network was enhanced when subjected to plasma with a bias voltage, compared to the process without a bias voltage. However, exposure to CH4/Ar plasma resulted in a deeper diffusion of IGZO atoms into the SiO2 network, primarily attributed to ion bombardment rather than elevated surface temperature. A significant improvement in surface smoothness was achieved after IGZO and SiO2 etch by introducing BCl3 into the SiO2 etching chemistry. [ABSTRACT FROM AUTHOR]

Organic batteries are one of the possible routes for transitioning to sustainable energy storage solutions. However, the recycling of organic batteries, which is a key step toward circularity, is not easily achieved. This work shows the direct recycling of poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl) (PTMA) and poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl acrylamide) (PTAm) based composite electrodes. After charge‐discharge cycling, the electrodes are deconstructed using a solubilizing‐solvent and then reconstructed using a casting‐solvent. The electrochemical properties of the original and recycled electrodes are compared using cyclic voltammetry (CV) and galvanostatic charge‐discharge (GCD) cycling, from which it is discovered using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) that recycling can be challenged by the formation of a cathode electrolyte interphase (CEI). In turn, an additive is proposed to modify the CEI layer and improve the properties after recycling. Last, an anionic rocking chair battery consisting of PTAm electrodes as both positive and negative electrodes is demonstrated, in which the electrodes are recycled to form a new battery. This work demonstrates the recycling of composite electrodes for organic batteries and provides insights into the challenges and possible solutions for recycling the next‐generation electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

It is known that X‐ray CT of organic polymer materials usually provides low‐contrast images because of the low X‐ray absorption of these materials. In this paper, we describe a new method to enhance the contrast of X‐ray CT images of organic polymer materials. We demonstrate that gamma‐ray irradiation of poly (ethylene terephthalate) (PET) fibers in dichloromethane containing 2‐bromoethyl methacrylate, 2‐chloroethyl methacrylate, or 4‐bromostyrene results in the grafting of halogen‐containing oligomeric chains onto the PET fibers. Focused ion beam scanning electron microscopy (FIB‐SEM) and time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analyses revealed a homogeneous distribution of bromine atoms within the 2‐bromoethyl methacrylate‐modified PET fibers, not only on the surface. This uniform incorporation translated to a significant improvement in X‐ray CT image contrast compared with pristine fibers. Similar treatment of polypropylene pellets also enhanced the contrast of their X‐ray CT images. This is a new simple and effective method to enhance the X‐ray CT image contrast and potentially applicable to various polymer materials including polymer composites and porous polymer materials, readily allowing the observation of their 3D microstructures finely. [ABSTRACT FROM AUTHOR]

The formation of effective interphases is crucial to enable high‐performance lithium‐ion batteries. This can be facilitated by the introduction of electrolyte additives, ensuring improved stability and transport properties. The identification of proper additives requires a comprehensive understanding of the fundamental mechanisms of interfacial reactions governing interphase formation. This study presents a detailed investigation of widely known and less conventional interphase‐forming additives in high‐voltage LiNi0.6Mn0.2Co0.2O2, NMC622||artificial graphite cells. The electrochemical characterization shows that cells containing vinylethylene carbonate (VEC) significantly outperform all other investigated electrolyte formulations. Surprisingly, gas chromatography‐mass spectroscopy measurements of the electrolyte composition after cycling indicate the formation of an ineffective solid‐electrolyte interphase (SEI) in the presence of VEC. A thorough analysis of the interfacial composition via operando shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) and surface‐enhanced Raman spectroscopy elucidates rather the formation of an effective cathode‐electrolyte interphase (CEI). This phenomenon results from the reductive reaction of VEC on the anode, followed by the product transfer and electro‐polymerization of reaction products on the cathode. Additionally, focused ion beam secondary ion mass spectrometry (FIB‐SIMS) with a time of flight (ToF)‐detector is used to analyze the elemental spatial distribution of Li‐species and Mn in the respective SEIs. [ABSTRACT FROM AUTHOR]

Diffusion of Ge donors in β‐Ga2O3 is studied using a combination of secondary‐ion mass spectrometry, diffusion simulations, and first‐principles calculations, and compared to previous studies on Sn diffusion. Ge is implanted into (2¯$\bar{2}$01)‐oriented samples and annealed at temperatures from 900 to 1050 °C for a total of 8 h. From previous first‐principles calculations, Sn is predicted to diffuse via the formation of a mobile complex with VGa that migrates through a sequence of exchange and rotation jumps. Herein, it is similarly predicted that Ge diffusion is mediated by VGa. However, the microscopic mechanism differs, as Ge can diffuse more easily through exchange combined with complex dissociation, rather than rotational jumps. This is explained by the difference in Ga‐site preference of Ge compared to Sn, and the three‐split mechanism that enables low migration barriers for VGa. The dissociation mechanism leads to a considerably faster transport for Ge as compared to Sn. The experimentally obtained Ge diffusion profiles are successfully fitted using a reaction–diffusion model based on the predicted diffusion mechanism, yielding a migration barrier of 2.5 ± 0.2 eV for the complex. The 2.72 eV obtained from first‐principles calculations is in good agreement with this value. [ABSTRACT FROM AUTHOR]

Objectives: Poly(amidoamine) dendrimers have been widely investigated as potential nanomaterials that can enhance the skin permeation of topically applied drugs. This article reviews the studies that have used dendrimers as penetration enhancers and examines the mechanisms by which enhancement is claimed. Key findings: A wide range of studies have demonstrated that, in certain circumstances and for certain drugs, the incorporation of dendrimers into a topically applied formulation can significantly increase the amount of drug passing into and through the skin. In some cases, dendrimers offered little or no enhancement of skin permeation, suggesting that the drug-dendrimer interaction and the selection of a specific dendrimer were central to ensuring optimal enhancement of skin permeation. Significant interactions between dendrimers and other formulation components were also reported in some cases. Summary: Dendrimers offer substantial potential for enhancing drug delivery into and across the skin, putatively by mechanisms that include occlusion and changes to surface tension. However, most of these studies are conducted in vitro and limited progress has been made beyond such laboratory studies, some of which are conducted using membranes of limited relevance to humans, such as rodent skin. Thus, the outcomes and claims of such studies should be treated with caution. Graphical Abstract [ABSTRACT FROM AUTHOR]

Samples of B‐type asteroid (101955) Bennu returned by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS‐REx) spacecraft will provide unique insight into the nature of carbonaceous asteroidal matter without the atmospheric entry heating or terrestrial weathering effects associated with meteoritic samples. Some of the Bennu samples will undergo characterization by X‐ray computed tomography (XCT). To protect the pristine nature of the samples, it is important to understand any adverse effects that could result from irradiation during XCT analysis. We analyzed acid‐insoluble residues produced from two powdered samples of the Murchison carbonaceous chondrite, one control and one XCT‐scanned, to assess the impact on insoluble organic matter (IOM) and presolar grains. Using a suite of in situ analytical techniques (field‐emission scanning electron microscopy, optical and ultraviolet fluorescence microscopy, microprobe two‐step laser mass spectrometry, and nanoscale secondary ion mass spectrometry), we found that the two residues had indistinguishable chemical, molecular, and isotopic signatures on the micron to submicron scale, indicating that an X‐ray dosage of 180 Gy (the maximum dose to be used during preliminary examination of Bennu materials) did not damage the IOM and presolar grains. To explore the use of acid‐insoluble residues to infer parent body processes in preparation for Bennu sample analysis, we also analyzed a residue produced from the Sutter's Mill carbonaceous chondrite. Multiple lines of evidence, including severely degraded UV fluorescence signatures and D‐rich hotspots, indicate that the parent body of Sutter's Mill was heated to >400°C. This heating event was likely short lived because the abundance of presolar SiC grains, which are destroyed by thermal metamorphism and prolonged oxidation, was consistent with those in Murchison and other unheated chondrites. The results of these in situ analyses of acid‐insoluble residues from Murchison and Sutter's Mill provide complementary detail to bulk analyses. [ABSTRACT FROM AUTHOR]

The conducting two‐dimensional electron gas (2DEG) behavior in LaAlO3 (LAO)/SrTiO3 (STO) and their associated mechanisms from various aspects have brought tremendous attention in the concerned area of research. To correlate the 2DEG behavior with their compositions, we have performed time of flight secondary ion mass spectrometry (TOF‐SIMS) depth profile analysis of thin films of Cr‐doped LAO/STO system as LaAl1‐xCrxO3 (x = 0, 0.2, 0.6 and 1) deposited over TiO2 terminated STO substrate, which includes two parent compounds LAO/STO (metallic) and LCO/STO (insulating). The uniform decrease of La and Al concentration at the interface of LAO/STO (metallic) system and in the contrary the nonuniformity of La and Cr concentration in LCO/STO (insulating) system have been highlighted. The uniform variation of ionic concentration at the interface of LAO/STO may increase the career concentrations to make the system metallic. The upward and downward diffusion at the interfaces of intermediate compositions varies differently from their parent ones due to the mixing of Al and Cr. Our results may help to understand the conducting nature of LAO/STO system for future developments and applications in such system. [ABSTRACT FROM AUTHOR]

In situ U-Th-Pb geochronology of monazite is widely used to reveal geological histories. Well characterized matrix-matched reference materials are crucial for achieving accurate results in microbeam U-Th-Pb dating. In this paper, the internal structure, chemical composition and U-Th-Pb dates of M6 monazite are investigated using multiple analytical methods to evaluate its potential as a reference material for in situ monazite U-Th-Pb dating. The results show that M6 monazite has an average ThO2 content of 10.7 ± 1.1% (2SD; SD = standard deviation) and Th/U ratio of 28.4 ± 3.3 (2SD). In situ U-Th-Pb dates from laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and secondary ion mass spectrometry (SIMS) laboratories are reproducible and homogeneous at the spatial level of 30 μm. Seven 207Pb/235U dates from isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) yield a mean date of 485.7 ± 2.3 Ma (2SD), which is our recommended date for M6 monazite. Furthermore, SIMS oxygen isotope determinations show good measurement reproducibility (7.70& ± 0.41&, 2SD) and the LA-MC-ICP-MS analyses yield homogeneous Sm-Nd isotopic composition (143Nd/144Nd = 0.511829 ± 0.000045, 2SD; 147Sm/144Nd = 0.2302 ± 0.0139, 2SD), demonstrating that M6 monazite has the potential to be a reference material for in situ O and Sm-Nd isotopic analyses. [ABSTRACT FROM AUTHOR]

Accurately determining the timing of hydrothermal mineralization for sediment-hosted disseminated gold (SHDG) deposits is difficult because of a lack of both suitable chronometers and in situ techniques with the required spatial resolution and precision. The lack of precise age determinations on gold deposits has hindered understanding of their genesis and relation to the geodynamic setting. The Qiuling-Jinlongshan deposit is a typical SHDG deposit located in the eastern South Qinling Orogen (SQO), with 109 t Au at an average grade of 6.17 g/t. Devonian and Carboniferous metasedimentary rocks host structurally controlled gold mineralization, which is associated with silica-carbonate alteration. Pyrite, arsenopyrite, and arsenian pyrite are major gold carriers, and gold also occurs as native gold grains and invisible gold in the sulfides. In this study, the well-defined hydrothermal overgrowth rims (~2 μm) of single monazite grains, associated with disseminated auriferous arsenian pyrite and arsenopyrite in low-grade metasedimentary rocks, yield U-Pb ages of239 ± 13 Ma (2σ) by high spatial resolution secondary ion mass spectrometry (SIMS). The hydrothermal monazites are cogenetic to the primary gold mineralization where they are closely associated with gold-bearing sulfides. This new age implies that the early to middle Triassic mineralization event in the eastern SQO was related to the Triassic tectonic transition from compression to transpression in the Qinling Orogen after the closure of the Mianlue Ocean. This study highlights the 2-μm high spatial resolution SIMS monazite U-Th-Pb dating method as a powerful tool for determining the timing of SHDG deposits worldwide. It is crucial to examine monazite textures and their link to hydrothermal alteration before carrying out the isotopic dating of monazite. [ABSTRACT FROM AUTHOR]

Objectives: Nitrogen isotopes (δ15N) are widely used to study human nursing and weaning ages. Conventional methods involve sampling 1‐mm thick sections of tooth dentine—producing an averaging effect that integrates months of formation. We introduce a novel protocol for measuring δ15N by multicollector secondary ion mass spectrometry (SIMS). Materials and Methods: We sampled dentine δ15N on a weekly to monthly basis along the developmental axis in two first molars of healthy children from Australia and New Zealand (n = 217 measurements). Nitrogen isotope ratios were determined from measurements of CN− secondary molecular ions in ~35 μm spots. By relating spot position to enamel formation, we identified prenatal dentine, as well as sampling ages over more than 3 years. We also created calcium‐normalized barium and strontium maps with laser ablation‐inductively coupled plasma‐mass spectrometry. Results: We found rapid postnatal δ15N increases of ~2‰–3‰, during which time the children were exclusively breastfed, followed by declines as the breastfeeding frequency decreased. After weaning, δ15N values remained stable for several months, coinciding with diets that did not include meat or cow's milk; values then varied by ~2‰ starting in the third year of life. Barium did not show an immediate postnatal increase, rising after a few months until ~1–1.5 years of age, and falling until or shortly after the cessation of suckling. Initial strontium trends varied but both individuals peaked months after weaning. Discussion: Developmentally informed SIMS measurements of δ15N minimize time averaging and can be precisely related to an individual's early dietary history. [ABSTRACT FROM AUTHOR]

Aqueous alteration in planetesimals is one of the earliest geological processes in the solar system. The timing of aqueous alteration sheds light on the timescale of material evolution through water–rock interaction in small bodies. The 53Mn-53Cr decay system, where a short-lived radionuclide 53Mn decays to 53Cr with a half-life of 3.7 Myr, is a powerful tool for dating carbonates in primitive meteorites that formed during aqueous alteration. In CI chondrites and samples returned from asteroid Ryugu, a major carbonate mineral is dolomite (CaMg(CO 3) 2) and could be dated precisely because of their relatively high Mn abundances. However, the lack of a proper dolomite standard for secondary ion mass spectrometry (SIMS) hinders us from obtaining accurate Mn/Cr ratios of carbonates, resulting in erroneous formation ages. In this work, we synthesized Mn-, Cr-, and Fe-bearing crystalline dolomite as standard materials and evaluated the relative sensitivity factor (RSF) of Mn/Cr for SIMS analysis, namely, the ratio of Mn/Cr obtained using SIMS to true Mn/Cr. We found that the RSF values of the dolomite standards range from 0.8 to 0.9, slightly higher than that of calcite (CaCO 3) (∼0.7), and increase with their Fe contents. We used the newly evaluated RSF values to date dolomite in the Ivuna CI chondrite and obtained an initial 53Mn/55Mn ratio of (3.95 ± 0.49) × 10−6 (95 % confidence interval) and the corresponding absolute age of 4564.0 + 0.6/−0.7 Ma. Our new initial 53Mn/55Mn ratio is 26 ± 19 % higher than that obtained by a previous study for the same dolomite grain using a calcite standard. This difference is consistent with the difference between the RSF values of dolomite and calcite. Based on these results, we updated the initial 53Mn/55Mn ratio previously reported for dolomite in the Ryugu sample A0058 to be (3.21 ± 0.66) × 10−6, which corresponds to an absolute age of 4562.8 + 1.0/−1.2 Ma. This age seems to be the best estimate for the formation age of dolomite in Ryugu currently available. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, the features of secondary emission phenomena were investigated under cluster bombardment. The emission of ion‐photons, secondary ions, and electrons associated with the thermal peak regime were experimentally carried out. The experiments were conducted using modernized a static magnetic mass spectrometer. The integral yield of secondary ion and electron emission was measured by bombarding Tb and Tm targets with cluster ions Aum− (m = 1–9) and Bim− (m = 1–7) within the energy range of 1–21 keV for the bombarding ions. Additionally, the integral yield of ion‐photon emission was measured by bombarding a Tm target with cluster ions Bim− (m = 1–5) within the same energy range. The experimental results showed that an increase in the yield of ion‐photon emission, secondary ion, and ion‐electron emission was observed with an increase in the number of atoms bombarded by cluster ions. This can be explained the formation of thermal peaks under dense collision cascades. [ABSTRACT FROM AUTHOR]

Aluminum scandium nitride barrier layers increase the available sheet charge carrier density in gallium nitride‐based high‐electron‐mobility transistors and boost the output power of high‐frequency amplifiers and high voltage switches. Growth of AlScN by metal‐organic chemical vapor deposition is challenging due to the low vapor pressure of the conventional Sc precursor Cp3Sc, which induces low growth rates of AlScN and leads to thermally‐induced AlScN/GaN‐interface degradation. In this work, novel Sc precursors are employed to reduce the thermal budget by increasing the growth rate of the AlScN layer. The AlScN/GaN interfaces are investigated by high‐resolution X‐ray diffraction, high‐resolution transmission electron microscopy, time‐of‐flight secondary ion mass spectrometry, capacitance–voltage, current–voltage and temperature‐dependent Hall measurements. Linearly graded interlayers with strain‐induced stacking faults, edge, and screw dislocations form at the AlScN/GaN interface at growth rates of 0.015 nms−1. Growth rates of 0.034 nms−1 and higher allow for abrupt interfaces, but a compositional grading in the barrier remains. Homogeneous barrier layers can be achieved at growth rates of 0.067 nms−1 or by growing an AlN interlayer. The electrical properties of the heterostructures are sensitive to Sc accumulations at the cap/barrier interface, residual impurities from precursor synthesis, and surface roughness. This study paves the way for high‐performing devices. [ABSTRACT FROM AUTHOR]

David Michael Hercules, a renowned scientist, passed away in 2024 after a battle with cancer. He was born in 1932 and developed an early interest in science and music. He pursued a career in science, earning a Bachelor's degree from Juniata College and a Ph.D. in analytical chemistry from MIT. Throughout his career, Hercules made significant contributions to various fields, including chemiluminescence, surface science, materials characterization, and mass spectrometry. He mentored over 130 graduate students and post-docs and emphasized the importance of confirming measurements with reference techniques. Hercules also engaged in industrial collaborations and encouraged his students to build expansive networks. He was known for his authenticity, warmth, and dedication to his students. [Extracted from the article]

Multilayer films of diamond‐like carbon (DLC) on monocrystalline diamond substrates have been for the first time obtained by plasma‐chemical deposition. Their chemical composition and structural and morphological properties are studied. The DLC individual layers differ in their sp3 carbon content. The multilayer nature of the resulting coatings is confirmed by periodic density modulation on the small‐angle X‐ray reflectometry curve and modulations in the CsC8, CsC6, CsC4 lines on the crater depth profile of secondary ions of elements (secondary ion mass spectrometry). The dependence of the deposition rate of multilayer DLC films on diamond, their composition and properties on the argon additive to the reaction gas mixture, as well as on methane flow, pressure and growth time, are studied. [ABSTRACT FROM AUTHOR]

Li/Mn‐rich layered oxide (LMR) offers high practical discharge capacity originating from both cationic and anionic redox, but its operation is practically challenging as full capacity utilization at high cathode potentials (> 4.6 V vs Li|Li+) is intertwined with phase transformation, oxygen release, and transition metal dissolution. Dissolved TMs in particular, can deposit and damage the anode via a process known as electrode cross‐talk that decreases Li inventory due to Li plating. Given the excess in active lithium, Li‐metal anode (LMA) is frequently paired with LMR for a systematic cathode R&D, though is believed to cause inverse cross‐talk, i.e., diffusion of LMA degradation products from the solid electrolyte interphase (SEI) toward the cathode, triggering bulid‐up of resistive cathode electrolyte interphase (CEI). Indeed, a thicker, more organic‐based, and slightly resistive CEI is proven in Li‐ compared to “SEI‐poor” Li4Ti5O12 (LTO)‐based cells via X‐ray photoelectron spectroscopy, time‐of‐flight secondary ion mass spectrometry, and electrochemical techniques, which likely even decreases metal dissolution from LMR, though their practical impact on overpotential is shown to be less relevant. The capacity recovery after transferring cycled (“old”) LMR from Li cells to fresh Li cells rather points to other meaningful contributions to capacity fading than the inverse crosstalk. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries are commonly used for energy storage due to their long lifespan and high energy density, but the use of unsafe electrolytes poses significant health and safety concerns. An alternative source is necessary to maintain electrochemical efficacy. This research demonstrates new safe glyme‐based electrolytes for silica/carbon (SiOx/C) nanocomposite derived from Australian rice husk (RH). The quality of SiOx/C was preserved by using deep eutectic solvent‐based pre‐treatment and single‐step carbonization, which was confirmed through the X‐ray analysis of the crystalline phase of silica. The electrochemical assessment of SiOx/C anode using various glyme‐based electrolytes for LIBs was carried out. Among them, the resultant half cells based on diglyme electrolyte is superior to others with the first discharge capacity at 1274 mAh/g and a reversible discharge capacity of 759.7 mAh/g. Ex‐situ SEM and Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐ SIMS) analysis of the electrode indicated that diglyme not only improves the capacity but also sustains the electrode architecture for longer cycle life with more LiF‐based components and also showed the absence of HF components. Importantly, the addition of fluoroethylene carbonate (FEC) additive enhanced the cycling stability. These results provide a new perspective on developing advanced SiOx/C anode using glyme electrolytes for Li‐ion batteries. [ABSTRACT FROM AUTHOR]

The increased difference in the sulfur isotopic compositions of sedimentary sulfate (carbonate‐associated sulfate: CAS) and sulfide (chromium‐reducible sulfur: CRS) during the Ediacaran Shuram excursion is attributed to increased oceanic sulfate concentration in association with the oxidation of the global ocean and atmosphere. However, recent studies on the isotopic composition of pyrites have revealed that CRS in sediments has diverse origins of pyrites. These pyrites are formed either in the water column/shallow sediments, where the system is open with respect to sulfate, or in deep sediments, where the system is closed with respect to sulfate. The δ34S value of sulfate in the open system is equal to that of seawater; on the contrary, the δ34S value of sulfate in the closed system is higher than that of seawater. Therefore, obtaining the isotopic composition of pyrites formed in an open system, which most likely retain microbial sulfur isotope fractionation, is essential to reconstruct the paleo‐oceanic sulfur cycle. In this study, we carried out multiple sulfur isotope analyses of CRS and mechanically separated pyrite grains (>100 μm) using a fluorination method, in addition to secondary ion mass spectrometry (SIMS) analyses of in situ δ34S values of pyrite grains in drill core samples of Member 3 of the Ediacaran Doushantuo Formation in the Three Gorges area, South China. The isotope fractionation of microbial sulfate reduction (MSR) in the limestone layers of the upper part of Member 3 was calculated to be 34ε = 55.7‰ and 33λ = 0.5129 from the δ34S and Δ33S' values of medium‐sized pyrite grains ranging from 100 to 300 μm and the average δ34S and Δ33S' values of CAS. Model calculations revealed that the influence of sulfur disproportionation on the δ34S values of these medium‐sized pyrite grains was insignificant. In contrast, within the dolostone layers of the middle part of Member 3, isotope fractionation was determined to be 34ε = 47.5‰. The 34ε value in the middle part of Member 3 was calculated from the average δ34S values of the rim of medium‐sized pyrite grains and the average δ34S values of CAS. This observation revealed an increase in microbial sulfur isotope fractionation during the Shuram excursion at the drill core site. Furthermore, our investigation revealed correlations between δ34SCRS values and CRS concentrations and between CRS and TOC concentrations, implying that organic matter load to sediments controlled the δ34SCRS values rather than oceanic sulfate concentrations. However, these CRS and TOC concentrations are local parameters that can change only at the kilometer scale with local redox conditions and the intensity of primary production. Therefore, the decreasing δ34SCRS values likely resulted from local redox conditions and not from a global increase in the oceanic sulfate concentration. [ABSTRACT FROM AUTHOR]

Isotope geochemistry requires isotope ratios measured using secondary ion mass spectrometry (SIMS) to be made with optimal precision and accuracy. Under some analytical conditions when using electron multiplier detectors, secondary ions may be under‐counted because of quasi‐simultaneous arrival (QSA) at the first dynode. The relative magnitude of the associated QSA correction to raw measured isotopic ratios can be up to seventy permil or more. Therefore, not applying the correction, or misapplication of it could lead to significant inaccuracies in published isotope ratio data. Examples and ramifications of the latter are described in addition to a straightforward procedure for QSA under‐counting correction. [ABSTRACT FROM AUTHOR]