Electron Energy Research Articles

Estimating the average energy of auroral electrons from 427.8 nm emission intensity measurements

We propose a method for estimating average energy of precipitating electrons from 427.8 nm emission intensity measurements. This method is based on the experimental dependence of the ratio of λ630.0 and λ427.8 nm emission intensities on the λ427.8 emission intensity and model calculations of the dependence of the average auroral electron energy on the I₆₃₀.₀/I₄₂₇.₈ ratio. We present numerical estimates of the influence of three factors on this dependence: the shape of the auroral electron energy spectrum, the atomic oxygen concentration, and the NO concentration. The dependence of the average energy of the auroral electron flux on the 427.8 nm emission intensity is obtained and its analytical approximation is presented.

Tuning optical and electronic properties of indanthrene derivatives with electron-withdrawing groups (-Cl, -NO₂ and -C≡N) for enhanced organic solar cell performance: a DFT approach

Abstract In this study, we focused on improving the electronic and optical properties of the reference compound indanthrene (R) by introducing electron-withdrawing groups (−Cl, −C≡N, −NO₂). density functional theory and time-dependent density functional theory calculations were performed using Gaussian 16 software to study indanthrene derivatives as electron acceptor materials. The electronic and optical properties of the designed molecules (M1-M8) were investigated through frontier molecular orbital analysis, UV-visible absorption spectra, density of states, and transition density matrix analysis, utilizing GaussView 6.0 and Multiwfn 3.8 software. The designed molecules exhibit absorption across the entire visible spectrum, with maxima extending up to ~737 nm. Their electron affinity values range from 3.0 to 4.0 eV, surpassing the fullerene-based acceptor material. Among the designed molecules, M5 stands out with superior photovoltaic parameters, including a narrow optical band gap (~1.68 eV), exciton binding energy (0.25 eV), higher electron affinity (3.35 eV), an extended excited state lifetime (17.0 ns) owing to its low electron and hole reorganization energies (λe ~ 0.190 eV, and λh ~ 0.134 eV), and improved short-circuit current density of ~ 15.7 mA/cm². The photovoltaic parameters and power conversion efficiency were assessed using the Scharber and Alharbi models. The calculated device parameters, including light harvesting energy and photovoltaic characteristics (Voc, FF, Jsc, and PCE), suggest that these molecules, with electron-withdrawing groups, show great potential for use as acceptors in organic solar cells, particularly in terms of stability and power conversion efficiency. Notably, M2 and M5, with their PCE values exceeding 16%, emerge as outstanding candidates for device performance, impressively outperforming the other designed molecules.

Design and analysis of diisobutoxybenzodithiophene based donor for application in organic solar cell: DFT and TD-DFT Study

The newly designed chromophores (BT1-BT7) of the highly unsaturated donor-acceptor (D-A) were theoretically analyzed and recommended for applications in organic solar cells (OSCs). Conjugated A-groups have been replaced in the reference (BTR) during its design. The structural and optoelectronic properties of designed molecules were calculated using density functional theory (DFT) and Time-dependent DFT (TD-DFT) techniques. The frontier molecular orbitals (FMO) study revealed that BT7 has the lowest energy gap of 2.01 eV, which has significantly less than BTR (2.34 eV), and a significant amount of charge transfer (CT) between HOMO and LUMO has been observed. Out of all the newly designed chromophores in chloroform, the highest absorption spectra were found in the visible region with a bathochromic shift up to 768 nm. The dipole moment values of all the new chromophores (BT1-BT7) were significantly higher than the BTR (5.46 D), which resulted in good solvation. ESP analysis revealed electron distribution on various parts of the molecules by colored maps that are found to be effective for better ICT. The electron transition density resulting from light absorption at different chemical sites was shown using TDM plots. The electron and hole reorganization energy (RE) values were proved as highly efficient in promoting charge mobility and hindered charge recombination for new compounds. By scaling our designed donor to the recognized acceptor Y6, which has demonstrated the creation of OSCs, the open circuit voltage of each molecule was ascertained. The designed molecules exhibited higher open circuit voltages than the reference, indicating improved and fine-tuned optoelectronic properties that would aid in the development of solar cell devices in the future.

Isolation and Characterization Lignin of Sugar Palm Fruit Shell by Klason Method

Sugar palm fruit shell is one of the biomass wastes that contains lignocellulose. Lignin is a valuable material that can be earned from the isolation of lignocellulosic material. In this work, lignin was isolated from palm fruit shell waste by Klason method with 72% sulfuric acid after removing free extractive by soxhlation process. The isolated lignin was analyzed to determine the functional groups, surface morphology, and thermal stability using Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-ray. This work aimed to isolate and characterize lignin from palm sugar fruit shells. The yield of lignin in this experiment was 27%. The water content, ash, and lignin pH obtained were 4.50%, 3.41% and 9.98. The Fourier Transform Infrared spectroscopy spectra showed the many functional groups contained in lignin, such as carbonyl, hydroxyl, amine, ether, methoxy, and aromatic components. The Scanning Electron Microscopy showed a rough and porous surface. The Energy Dispersive X-ray showed the elemental composition in lignin, such as carbon, oxygen, and some inorganic elements. The Thermogravimetric Analysis showed that weight loss of lignin reached 47.948 % or 5.082 mg at 600°C. The characteristics of lignin obtained from sugar palm fruit shell by Klason showed that it had potency as a good material for further application.

Image analysis of kimchi cabbage penetrated with brine and seasoning using a serial block face scanning electron microscope and energy dispersive X-ray spectroscopy

Image analysis of kimchi cabbage penetrated with brine and seasoning using a serial block face scanning electron microscope and energy dispersive X-ray spectroscopy

Оценка средней энергии потока авроральных электронов по измерению интенсивности излучения эмиссии λ427.8 нм

We propose a method for estimating average energy of precipitating electrons from 427.8 nm emission intensity measurements. This method is based on the experimental dependence of the ratio of λ630.0 and λ427.8 nm emission intensities on the λ427.8 emission intensity and model calculations of the dependence of the average auroral electron energy on the I₆₃₀.₀/I₄₂₇.₈ ratio. We present numerical estimates of the influence of three factors on this dependence: the shape of the auroral electron energy spectrum, the atomic oxygen concentration, and the NO concentration. The dependence of the average energy of the auroral electron flux on the 427.8 nm emission intensity is obtained and its analytical approximation is presented.

Molecular-scale kinetic Monte Carlo simulation of pattern formation in photoresist materials for EUV nanolithography

A kinetic Monte Carlo (KMC) simulation tool for modeling the pattern formation process in photoresist materials for extreme ultraviolet (photon energy 92 eV) nanolithography is presented. The availability of such a tool should support the progress toward novel materials and experimental procedures that lead to an improved pattern resolution. The molecular-scale simulations describe the process in a stochastic and mechanistic manner and include the excitation of high-energy electrons upon light absorption, the creation of a charged-particle cloud, electron-induced chemical degradation of the photoresist molecules, the resulting bond formation between neighboring degraded molecules, and a chemical development step after which a pattern of the remaining non-dissolved molecules is obtained. The method is applied to the application-relevant class of Sn-oxocore photoresist materials and uses their known electronic structure and optical electron energy loss function. The validity of the approach is tested by comparing measured and simulated total electron yield spectra and photoelectron spectra. A demonstration of the method is given by calculating the dose and pitch dependent average shape and stochastic variability (line edge roughness) of line patterns that are obtained for rectangular and sine-wave illumination, assuming various scenarios that determine how molecular-scale degradation will lead to bond creation. We show how from these simulations the ultimate pattern resolution can be deduced. The findings are analyzed systematically using results of KMC simulations that reveal the size of the cloud of degraded molecules around a point of absorption (blur length) and that further reveal the sensitivity to uniform illumination (contrast curves), and using percolation theory. We find that KMC modeling captures the consequences of the strong gradients in the density of degraded molecules and of the stochasticity of the patterning process that simplified models do not include, leading to a significantly improved view of the final pattern quality.

Green Synthesis of Quercetin-Coated Ecofriendly Zirconium Oxide Nanoparticles and Evaluating its in vitro Biological Activities

The development of nanomaterials using green synthesis methods is gaining attention due to their potential to reduce environmental pollution and health risks associated with traditional chemical synthesis methods. Among the various transition metals, zirconia has gained significant interest as filling materials and implants in dentistry due to its excellent mechanical and chemical properties. In this study, we developed ecofriendly zirconium oxide nanoparticles using Biancaea sappan extract as a capping agent and then functionalized them with Quercetin. Further, their anti-inflammatory property and hemocompatibility were evaluated to target their application as filling materials. The biogenic zirconium oxide nanoparticles (B-ZrO2NPs) and quercetin functionalized biogenic zirconium oxide nanoparticles (BQZN) were characterized by UV–Vis Spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy X-ray analysis (EDX). B-ZrO2NPs showed maximum absorbance at 267[Formula: see text]nm and 383[Formula: see text]nm. FTIR showed characteristic stretching at 3381[Formula: see text]cm[Formula: see text], confirming the O–H group in the extract and Quercetin used for BQZN formation. The FTIR spectra of BQZN displayed the presence of the characteristic peaks observed in the spectra of B-ZrO2NPs and Quercetin. The broad XRD pattern confirmed the amorphous nature of the zirconia. SEM revealed the spherical morphology of B-ZrO2NPs and BQZN with a size range of around 90[Formula: see text]nm and 120[Formula: see text]nm, respectively. EDAX of BQZN revealed the presence of 45.7[Formula: see text]wt.% Zr, 32.9% oxygen and 21.4% of carbon. In vitro bioactivity studies revealed that BQZN exhibited significant anti-inflammatory activity, as evidenced by the inhibition of protein denaturation. The nanoparticles were also demonstrated for their hemocompatibility with erythrocytes. These findings highlight the potential of BQZN as a promising hemocompatible dental filling with significant anti-inflammatory properties. Further in-depth in vivo studies are required to fully understand their efficacy and toxicity.

Advancements in Ge-Based Thermoelectric Materials for Efficient Waste Heat Energy Conversion: A Comprehensive Review

Abstract Thermoelectric materials hold significant promise for converting waste heat energy into electrical energy. The performance of these materials and devices is assessed using a quantitative measure known as the figure of merit, which relies on the Seebeck coefficient, thermal conductivity, and electrical conductivity of the material. Extensive efforts have been devoted to enhancing the efficiency of thermoelectric materials and devices through various techniques such as doping, nanostructuring, electron energy filtering, and band engineering. This paper presents a comprehensive review encompassing various thermoelectric materials, including organic, inorganic, intermetallic, complex cell structures, hybrid, and notably Germanium-based materials. Ge, due to its easy availability, low cost, high Seebeck coefficient, and high thermal stability, emerges as a suitable candidate for thermoelectric energy generation. Among the Ge-based materials studied, (Sb2Te3)0.5(Ge0.91Pb0.09Te)17.5 gave the highest figure of merit, with values of approximately 2.4 at 773 K. These findings underscore the significant potential of GeTe alloy in thermoelectric energy harvesting. This review provides an overview of the latest developments in thermoelectric materials, focusing on different strategies to enhance thermoelectric performance. Additionally, the suitability of various Ge-based thermoelectric materials for energy harvesting applications is extensively discussed in this review.

Dissociative excitation of acetone induced by electron impact

Abstract We report the results of an experimental study focused on the low-energy (10-100 eV) electron impact excitation of acetone. In the emission spectrum, the most prominent excited species were found to be the hydrogen Balmer series, the excited CH radical in the A and B electronic states, and atomic carbon. The presence of OH emission in the spectra confirms the tautomerization process induced by electron impact. The acetone emission spectra were measured at several different reaction energies, forming a unique 3D spectral electron energy map. Excitation-emission functions were determined for selected most prominent products.

Ba/Ti MOF: A Versatile Heterogeneous Photoredox Catalyst for Visible-Light Metallaphotocatalysis.

The field of sustainable heterogeneous catalysis is evolving rapidly, with a strong emphasis on developing catalysts that enhance efficiency. Among various heterogeneous photocatalysts, metal-organic frameworks (MOFs) have gained significant attention for their exceptional performance in photocatalytic reactions. In this context, contrary to the conventional homogeneous iridium or ruthenium-based photocatalysts, which face significant challenges in terms of availability, cost, scalability, and recyclability, a new Ba/Ti MOF (ACM-4) is developed as a heterogeneous catalyst that can mimic/outperform the conventional photocatalysts, offering a more sustainable solution for efficient chemical processes. Its redox potential and triplet energy are comparable to or higher than the conventional catalysts, organic dyes, and metal semiconductors, enabling its use in both electron transfer and energy transfer applications. It facilitates a broad range of coupling reactions involving pharmaceuticals, agrochemicals, and natural products, and is compatible with various transition metals such as nickel, copper, cobalt, and palladium as co-catalysts. The effectiveness of the ACM-4 as a photocatalyst is supported by comprehensive material studies, photophysical, and recycling experiments. These significant findings underscore the potential of ACM-4 as a highly versatile and cost-effective photoredox catalyst, providing a sustainable, one-material solution for efficient chemical processes.

Single‐Crystal and Polycrystal SiC Bonding for Cost‐effective Chip Fabrication

AbstractHigh‐quantity single‐crystal silicon carbide (SiC) is widely used in power electronics due to its excellent breakdown electric field strength and high thermal conductivity. However, back grinding during the chip fabrication generally results in ≈70% of single‐crystal SiC being wasted, leading to the high cost of SiC chips. In order to improve the utilization, single‐crystal SiC on polycrystal SiC (SoP‐SiC) is bonded. The challenge to achieve excellent bonding interfaces for such a system is the heterogeneous surface of polycrystals in which those grains with different orientations usually have different physical and chemical properties, making it difficult to achieve sufficiently smooth surfaces for bonding. Here, ion beam etching (IBE) is employed to activate the surface of polycrystal and single‐crystal SiC and achieve high bonding strength (up to ≈20 MPa) after annealing in the atmosphere. Sub‐nanometer‐scale electron microscopy and energy spectroscopy analysis showing the IBE method can effectively inhibit the formation of silicon oxide at the bonding interface, which is expected to reduce the interface thermal resistance according to the phonon spectrum analysis. This study provides a novel method to fabricate single‐polycrystal SiC junctions with high bonding strength and high thermal conductivity, which is valuable for the SiC industry.

Spectroscopic Signatures of Ultra-Thin Amorphous Carbon with the Tuned Disorder Directly Grown on a Dielectric Substrate.

The reduced structural complexity of atomically thin amorphous carbons makes it suitable for semiconductor technology. Inherent challenges arise from transfer processes subsequent to growth on metallic substrates, posing significant challenges to the accurate characterization of amorphous materials, thereby compromising the reliability of spectroscopic analysis. Here this work presents a novel approach: direct growth of ultra-thin amorphous carbon with tuned disorder on a dielectric substrate (SiO2/Si) using photochemical reaction and thermal annealing process with a solid precursor. This work characterizes the amorphous carbon films' disorder using spectroscopic techniques, such as X-ray photoelectron spectroscopy, Electron energy loss spectroscopy, and Raman spectroscopy, which offer greater convenience compared to microscopy-based studies. This method, rooted in comprehensive spectroscopic characterization, elucidates characteristic signatures inherent to the amorphous carbon films. These findings reveal that Raman spectroscopy is particularly effective in identifying the amorphous phase of atomically-thin carbon. Additionally, I-V characterization and high-frequency dielectric measurements showcase the potential application of directly grown amorphous carbon films in the semiconductor industry, where nanometer-level thin conductors and dielectrics are commonly utilized. This transfer-free characterization method provides a useful tool to find the correlation between atomic structure and electrical/optical properties, giving valuable insights into comprehensive crystallographic fundamental research.

Lubricity performance of Jatropha oil incorporated PTFE and h-BN as additives for electric vehicles transmission lubrication

Purpose Concerns over the pollution caused by internal combustion vehicles have increased owing to population and industrialization increment. Addressing the confrontations, the demand for electric vehicles (EVs) as a combustion engine substitute became necessary in responding to environmental worries from internal combustion. The development of bio lubricant in lubricating the sliding parts of EVs is required to maintain the sustainability idea and to improve the system performance, which this research tends to explore. Design/methodology/approach In this research, the enhancement of base Jatropha oil was done using polytetrafluoroethylene (PTFE) and hexagonal boron nitrate (h-BN) as additives. Different characterization was conducted on the new formulation to ascertain its anticorrosion tendency. The wear and friction behavior of the formulations on the tribo-pairs surfaces in contact were investigated using ball on flat tribometer to determine their tribological responsiveness as mineral lubricant alternative. To explore the surface topography, surface profilometer, scanning electron microscope and energy dispersive X-ray investigations were PTFE, lubrication and EV carried out. Findings The test’s input parameters were EVs’ usual load and sliding speed, and the addition concentrations for PTFE were 0.3 Wt.%, 0.4 Wt.%, 0.5 Wt.% and 0.6 Wt.%, whereas h-BN were 0.4 Wt.%, 0.8 Wt.% and 1.2 Wt.%, respectively. The study on corrosion demonstrated resistance when applied PTFE and h-BN additives in Jatropha oil. The analysis revealed that 0.5 Wt.% PTFE + 0.8 Wt.% h-BN concentrations significantly improved the tribological characteristics when compared to the base Jatropha oil. The application of formulations yielded percentage reduction of 8.67%, 10.98%, 7.34% and 7.35%, respectively, for 0.5% poly + 0.5% h-BN, 0.5% poly + 0.6% h-BN, 0.5% poly + 0.7% h-BN, 0.5% poly + 0.8% h-BN against base Jatropha oil under 20 N. Originality/value The formulation of PTFE and h-BN for electric transmission with wear and friction effects was accomplished in this paper. The mechanism of particle diffusing at the sliding contact on tribological behavior could be examined based on the created model of operation. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0235/

Reducing Lithium‐Diffusion Barrier on the Wadsley–Roth Crystallographic Shear Plane via Low‐Valent Cation Doping for Ultrahigh Power Lithium‐Ion Batteries

AbstractRapid‐charging niobium–tungsten oxide Nb14W3O44 (NbWO) anodes with a Wadsley–Roth crystallographic shear (WRCS) structure possess 3D interconnected open tunnels. However, the anisotropic Li+ diffusion paths lead to a high lithium‐diffusion barrier of hooping between window sites across edge‐shared octahedrons, as the rate‐limiting step of hooping. To improve the rate capability of NbWO, doping it with low‐valent cations (with valences lower than W6+) to reduce the high lithium‐diffusion barrier is proposed. Electron energy loss spectroscopy reveals that low‐valent V5+, V4+, Tb4+, and Ce4+ tend to distribute on the crystallographic shear plane under electrostatic repulsion forces. The reduction in steric hindrance resulting from the increased long bond length ratio of doped edge‐shared octahedrons, coupled with coordination environment modification of [LiO5] on the crystallographic shear plane due to the low energy level of V5+, enhances Li+ diffusion kinetics and cyclic stability. V5+‐ and Tb4+‐doped NbWOs achieve rate capacities of 83 and 63 mAh g−1, at 200 C (1C = 0.178 Ag−1) and retain 75.42% and 86.79% of their capacities, respectively, after 3700 cycles at 20 C. Thus, the proposed doping strategy is promising for preparing WRCS‐type niobium‐based oxides for ultrafast lithium storage.

Tailored pseudopotentials for magnesium surface core level shift calculations

In x-ray photoelectron spectroscopy (XPS), identifying the origin of peaks in the spectrum can be guided by theory calculations. With density functional theory (DFT), using pseudopotentials, one can obtain the difference in photoelectron energy for electrons originating from atoms of different environments, for example surface and bulk atoms, and thus model the surface core level shift (SCLS) energies. The focus in this work is to prepare for calculations of magnesium (Mg) 2p SCLSs in material systems where dispersion interactions play a role, primarily in Mg surface degradation and adsorption of molecules as relevant, for example, in degradable bioimplants. For SCLS DFT calculations in metallic surfaces, the state of the photoelectron must be treated as a core state. In the case of Mg, standard pseudopotentials treat the 2p state as a valence state, not a core state. We therefore need Mg pseudopotentials with the 2p electrons in the core, leaving only two electrons for the valence region (the 3s electron); Two-valence electron pseudopotentials are not common, because DFT calculations of Mg-containing materials usually are better or more easily described using 10 valence electrons. In this work, new two-electron Mg pseudopotentials are therefore created for use in dispersion-inclusive DFT calculations. To our knowledge, no such two-electron Mg pseudopotentials exist, proven to work well with the nonlocal, dispersion-inclusive, exchange-correlation functional vdW-DF-cx or similar functionals. We create a number of two-electron Mg pseudopotentials and their 2p-hole partners, and for four of the most promising we assess their performance in vdW-DF-cx. We provide results for Mg and MgO bulk phases and for the Mg(0001) surface energy, structure, and SCLS, and where possible we compare with results that we obtain by using conventional 10-electron Mg pseudopotentials, all-electron calculations, and with experiments. This work not only reports and tests the specific conditions for creating 2p Mg results, it will also, we believe, be of help in creating other similar pseudopotentials to aid the analysis of XPS spectra in other materials. Published by the American Physical Society 2024

A multimass velocity-map and covariance-map imaging study of the dissociative electron ionisation dynamics of carbonyl sulphide (OCS)

Abstract We present the results of a velocity-map imaging study into the dissociative electron ionisation dynamics of OCS at electron energies of 50, 75, and 100 eV, supported by new EOM-CCSD and CASSCF potential energy surface calculations for the OCS+ cation and OCS2+ dication. We report partial ionisation cross-sections and scattering distributions for the observed ionic fragments, and interpret these in terms of the dissociation dynamics of the singly and doubly charged OCS parent ions formed in the electron-molecule collisions. For many of the dissociation channels, consideration of the calculated potential energy surfaces supplemented by comparison with data from photoionisation studies provides insight into the electronic potential energy surfaces involved. For fragmentation products arising from dissociation of the dication, time-of-flight and recoil-frame covariance maps provide mechanistic insight into the stepwise dissociation mechanisms leading to these products and support previous conclusions by other authors.

Modeling the effects of electron irradiation on graphene drums using the local activation model

We study the effects of electron irradiation on suspended graphene monolayers and graphene supported on SiO2 substrates in the range 5.0 × 1015–4.3 × 1017 electrons/cm2. The suspended graphene monolayers are exfoliated over SiO2 substrates containing micrometer-sized holes, with graphene completely covering the hole, and are referred to as graphene drums. The irradiation was performed using a scanning electron microscope at 20–25 keV electron energy. We observe a two-stage behavior for the ID/IG, ID′/IG, and ID/ID′ ratios as a function of the average distance between defects, LD, where ID, IG, and ID′ are the intensities of the Raman D, G, and D′ peaks, respectively. Good fits to the dependence of the ratios on LD are obtained using the local activation model equation. The fits are used to characterize the defects at high defect densities. We also carried out annealing studies of samples irradiated to the first stage and used an Arrhenius plot to measure activation energies for defect healing, Ea. We measured Ea = 0.90 eV for the graphene drums, consistent with the hydroxyl groups; for supported graphene, we measured Ea = 0.36 eV, consistent with hydrogen adsorbates. We also studied the surface of the drums using atomic force microscopy and found no observable holes after irradiation and annealing. Our results show that the local activation model is useful in characterizing the defects in graphene drums.

Mechanical Characterization of Main Minerals in Carbonate Rock at the Micro Scale Based on Nanoindentation

The mechanical characterization of carbonate rock is crucial for the development of a hydrocarbon reservoir and underground gas storage. As a kind of natural composite material, the mechanical properties of carbonate rock exhibit multiscale characteristics. The macroscopic mechanical properties of carbonate rock are determined by the mineral composition and structure at the micro scale. To achieve a mechanical investigation at the micro scale, this study designed a scheme for micromechanical characterization of carbonate rock. First, scanning electron microscope observation and energy dispersive spectroscopy analysis were combined to select the appropriate micromechanical test areas and to identify the mineral types in each area. Second, the selected test area was positioned in the nanoindentation instrument through the comparison of different-type microscopic images. Finally, quasi-static nanoindentation was carried out on the surface of different minerals in the selected test area to obtain quantitative mechanical evaluation results. A typical carbonate rock sample from the Huangcaoxia gas storage was investigated in this study. The experimental results indicated apparent micromechanical heterogeneity in the carbonate rock. The Young’s modulus of pyrite was over 200 GPa, while that of clay minerals was only approximately 50 GPa. In addition, the proposed micromechanical characterization scheme was discussed based on experimental results. For minerals with an unknown Poisson’s ratio, the maximum error introduced by the 0.25 assumption was lower than 15%. To discuss the effectiveness of the nanoindentation results, the characterization abilities constituted by lateral spatial resolution and elastic response depth were analyzed. The analysis results revealed that the nanoindentation measurement of clay was more susceptible to influence by the surrounding environment as compared to other kinds of minerals with the experimental setup in this study. The micromechanical characterization scheme for clay minerals can be optimized in future research. The mechanical data obtained at the micro scale can be used for the interpretation of the macroscopic mechanical features of carbonate rock for the parameter input and validation of mineral-related simulation and for the construction of a mechanical upscaling model.

High-resolution electron energy analyzer with wide acceptance angle for hard X-ray photoelectron holography: integrating PESCATORA and retarding field analyzer

Abstract Photoelectron holography requires measuring the photoelectron angular distribution across a wide acceptance angle, typically exceeding ±45°. This necessitates an electron analyzer that offers both a large acceptance angle and high energy resolution for kinetic energies ranging from several hundred to several thousand eV. Our previously developed high-resolution retarding field analyzer (RFA) achieves excellent energy resolution. However, its close electrode spacing limits operation at high voltages (several thousand eV). To address this limitation, we propose a novel electron analyzer that combines a parallelizing electron lens (PESCATORA) with an RFA. The PESCATORA lens parallelizes the trajectories of photoelectrons. Subsequently, the RFA decelerates and analyzes their energy. This two-stage approach allows for a sufficient distance between the RFA electrodes, enabling high-voltage operation. The resulting analyzer functions as a high-pass filter with a sharp energy cut-off. By incorporating lock-in detection, this system can be further worked as a bandpass electron analyzer. Our simulation also suggests that a specially designed mesh electrode within the RFA allows bandpass operation without the need for lock-in detection.