Pub Date : 2025-08-01Epub Date: 2025-06-21DOI: 10.1016/j.elspec.2025.147552
Munendra Jain , Ghanshyam Purohit , Wolfgang Quint
The high-energy electron impact ionization of atoms is a significant phenomenon in understanding atomic behaviour, and it can provide valuable information related to electron-atom scattering. In the case of the nuclear fusion process, electron and atom scattering done at high energy can provide precious information. In the present study, we report triple differential cross-sections (TDCS) and spin asymmetry for tungsten atoms’ electron impact K shell ionization at relativistic energies regime. The relativistic distorted wave Born approximation (rDWBA) formalism has been used with the coplanar asymmetric geometrical arrangement to calculate TDCS and spin asymmetry. The TDCS and spin asymmetry have been calculated for the high incident energy from 250 keV to 700 keV, for various scattering angles , , and to create consistent with findings of (e, 2e) experiments of Schule and Nakel.
{"title":"Unravelling Tungsten atom ionization at high energies: A relativistic electron impact study","authors":"Munendra Jain , Ghanshyam Purohit , Wolfgang Quint","doi":"10.1016/j.elspec.2025.147552","DOIUrl":"10.1016/j.elspec.2025.147552","url":null,"abstract":"<div><div>The high-energy electron impact ionization of atoms is a significant phenomenon in understanding atomic behaviour, and it can provide valuable information related to electron-atom scattering. In the case of the nuclear fusion process, electron and atom scattering done at high energy can provide precious information. In the present study, we report triple differential cross-sections (TDCS) and spin asymmetry for tungsten atoms’ electron impact K shell ionization at relativistic energies regime. The relativistic distorted wave Born approximation (rDWBA) formalism has been used with the coplanar asymmetric geometrical arrangement to calculate TDCS and spin asymmetry. The TDCS and spin asymmetry have been calculated for the high incident energy from 250 keV to 700 keV, for various scattering angles <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>o</mi></mrow></msup></math></span>, <span><math><msup><mrow><mn>5</mn></mrow><mrow><mi>o</mi></mrow></msup></math></span>, <span><math><msup><mrow><mn>8</mn></mrow><mrow><mi>o</mi></mrow></msup></math></span> and <span><math><mrow><mn>1</mn><msup><mrow><mn>4</mn></mrow><mrow><mi>o</mi></mrow></msup></mrow></math></span> to create consistent with findings of (e, 2e) experiments of Schule and Nakel.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"281 ","pages":"Article 147552"},"PeriodicalIF":1.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-06-09DOI: 10.1016/j.elspec.2025.147545
Sana Mekhalfa , Salim Houamer , Abdelaziz Mansouri , Imene Khiat , Ayoub Tamin , Claude Dal Cappello , Paul-Antoine Hervieux
Calculations of the triple differential cross section (TDCS) for positron and electron impact ionization have been performed for the inner as well as the outer orbitals of nitrogen molecule, within a model developed for molecular targets and called M3CWZ. In this model, a full Coulomb wave scheme with variable charges to describe the continuum particles is used, taking into account the post collision interaction (PCI). Experiments performed in asymmetric geometries at large and lower recoil momentum have been investigated for the outer (, and) as well as the inner orbitals, comparison is then made between experimental data and theory. At intermediate impact energies (up to 700 eV), it is found that the M3CWZ model is able to predict the general trends of the TDCS for the outer orbitals at large recoil momentum when the residual ion plays substantial role, better than other sophisticated models. For the inner orbital the large intensity of the TDCS observed in the recoil region is not correctly reproduced by the present calculations. At lower 250 eV impact energy, a moderate agreement with the data is achieved for outer orbital.
{"title":"Theoretical investigation of the triple differential cross section in the nitrogen molecule ionization by electron and positron impact","authors":"Sana Mekhalfa , Salim Houamer , Abdelaziz Mansouri , Imene Khiat , Ayoub Tamin , Claude Dal Cappello , Paul-Antoine Hervieux","doi":"10.1016/j.elspec.2025.147545","DOIUrl":"10.1016/j.elspec.2025.147545","url":null,"abstract":"<div><div>Calculations of the triple differential cross section (TDCS) for positron and electron impact ionization have been performed for the inner as well as the outer orbitals of nitrogen molecule, within a model developed for molecular targets and called M3CWZ. In this model, a full Coulomb wave scheme with variable charges to describe the continuum particles is used, taking into account the post collision interaction (PCI). Experiments performed in asymmetric geometries at large and lower recoil momentum have been investigated for the outer (<span><math><mrow><mn>2</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></math></span>, <span><math><mrow><mn>1</mn><msub><mrow><mi>π</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></math></span>and<span><math><mrow><mn>3</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow></math></span>) as well as the inner <span><math><mrow><mn>2</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow></math></span> orbitals, comparison is then made between experimental data and theory. At intermediate impact energies (up to 700 eV), it is found that the M3CWZ model is able to predict the general trends of the TDCS for the outer orbitals at large recoil momentum when the residual ion plays substantial role, better than other sophisticated models. For the inner <span><math><mrow><mn>2</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow></math></span> orbital the large intensity of the TDCS observed in the recoil region is not correctly reproduced by the present calculations. At lower 250 eV impact energy, a moderate agreement with the data is achieved for outer <span><math><mrow><mn>3</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>g</mi></mrow></msub></mrow></math></span>orbital.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"281 ","pages":"Article 147545"},"PeriodicalIF":1.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-06-02DOI: 10.1016/j.elspec.2025.147542
J. Braun
Various apparative developments extended the potential of angle-resolved photoemission spectroscopy tremendously during the last decades. Modern experimental arrangements consisting of new photon sources, analyzers and detectors supply not only extremely high angle and energy resolution but also spin resolution. This provides an adequate platform to study in detail new materials like low-dimensional magnetic structures, Rashba systems, topological insulator materials or high T superconductors. The interest in such systems has grown enormously not only because of their technological relevance but even more because of exciting new physics. Furthermore, the use of photon energies from few eV up to several keV makes this experimental technique a rather unique tool to investigate the electronic properties of solids and surfaces. The following article presents a recent theoretical development in the field of angle-resolved photoemission with a special emphasis on time-resolution. In detail, a theoretical frame for two-photon photoemission spectroscopy is introduced. The approach is based on a general formulation using the Keldysh formalism for the lesser Green’s function to describe the real-time evolution of the electronic degrees of freedom in the initial state after a sufficiently weak pump pulse drives the system out of equilibrium. Assuming that not only the probe but also the pump pulse is relatively weak, a perturbative approach can be formulated that allows to compute the lesser Green function explicitly for real systems in terms of the corresponding retarded and advanced Keldysh Green functions. The final state is represented by a time-reversed low-energy electron diffraction state. This so called two-photon photoemission spectroscopy is a widely used analytical tool to study non-equilibrium phenomena in solid materials. The theoretical approach presented here aims at a material-specific, realistic and quantitative description of the time-dependent spectrum based on a picture of effectively independent electrons as described by the local-density approximation in band-structure theory.
{"title":"Relativistic theory of 2PPE","authors":"J. Braun","doi":"10.1016/j.elspec.2025.147542","DOIUrl":"10.1016/j.elspec.2025.147542","url":null,"abstract":"<div><div>Various apparative developments extended the potential of angle-resolved photoemission spectroscopy tremendously during the last decades. Modern experimental arrangements consisting of new photon sources, analyzers and detectors supply not only extremely high angle and energy resolution but also spin resolution. This provides an adequate platform to study in detail new materials like low-dimensional magnetic structures, Rashba systems, topological insulator materials or high T<span><math><msub><mrow></mrow><mrow><mi>C</mi></mrow></msub></math></span> superconductors. The interest in such systems has grown enormously not only because of their technological relevance but even more because of exciting new physics. Furthermore, the use of photon energies from few eV up to several keV makes this experimental technique a rather unique tool to investigate the electronic properties of solids and surfaces. The following article presents a recent theoretical development in the field of angle-resolved photoemission with a special emphasis on time-resolution. In detail, a theoretical frame for two-photon photoemission spectroscopy is introduced. The approach is based on a general formulation using the Keldysh formalism for the lesser Green’s function to describe the real-time evolution of the electronic degrees of freedom in the initial state after a sufficiently weak pump pulse drives the system out of equilibrium. Assuming that not only the probe but also the pump pulse is relatively weak, a perturbative approach can be formulated that allows to compute the lesser Green function explicitly for real systems in terms of the corresponding retarded and advanced Keldysh Green functions. The final state is represented by a time-reversed low-energy electron diffraction state. This so called two-photon photoemission spectroscopy is a widely used analytical tool to study non-equilibrium phenomena in solid materials. The theoretical approach presented here aims at a material-specific, realistic and quantitative description of the time-dependent spectrum based on a picture of effectively independent electrons as described by the local-density approximation in band-structure theory.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"281 ","pages":"Article 147542"},"PeriodicalIF":1.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-07-09DOI: 10.1016/j.elspec.2025.147553
Igor Novak
The vertical, valence ionization energies for several bicyclic alkenes containing geometrically distorted π CC bonds in bridgehead positions have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. We have selected bridgehead alkenes (BA) which have been either accessed as intermediates (e.g. in trapping reactions) or have been synthesized experimentally and classified as hyper-stable (based on reactivity deduced from theoretical calculations). We investigated changes in various parameters within isomeric pairs: one molecule being bridged the other non-bridged. The variations in vertical ionization energies were related to other electronic and structural parameters of BAs. The π-bond positioned at the junction of two rings (bridge) leads to its twisting and pyramidalization. This is reflected in the following changes in BA: decrease of the 1st ionization energy, reduction of HOMO-LUMO and singlet-triplet gaps, increased polarization of CC bond and increased standard enthalpy of formation of bridged vs. non-bridged isomer.
{"title":"Photoionization and electronic structure of bridgehead alkenes","authors":"Igor Novak","doi":"10.1016/j.elspec.2025.147553","DOIUrl":"10.1016/j.elspec.2025.147553","url":null,"abstract":"<div><div>The vertical, valence ionization energies for several bicyclic alkenes containing geometrically distorted π C<img>C bonds in bridgehead positions have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. We have selected bridgehead alkenes (BA) which have been either accessed as intermediates (e.g. in trapping reactions) or have been synthesized experimentally and classified as hyper-stable (based on reactivity deduced from theoretical calculations). We investigated changes in various parameters within isomeric pairs: one molecule being bridged the other non-bridged. The variations in vertical ionization energies were related to other electronic and structural parameters of BAs. The π-bond positioned at the junction of two rings (bridge) leads to its twisting and pyramidalization. This is reflected in the following changes in BA: decrease of the 1st ionization energy, reduction of HOMO-LUMO and singlet-triplet gaps, increased polarization of C<img>C bond and increased standard enthalpy of formation of bridged vs. non-bridged isomer.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"281 ","pages":"Article 147553"},"PeriodicalIF":1.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-07-08DOI: 10.1016/j.elspec.2025.147554
A.P. Chaynikov, A.G. Kochur, A.I. Dudenko
Cascade decays of single vacancies in K to N shells of the Pt atom are studied by construction and analysis of the decay trees. Energies of cascade-produced multivacancy configurations and decay branching ratios are calculated in Pauli–Fock approximation. The role of multiplet splitting and multiplet overlapping in calculating mean transition energies and ionic configurations branching ratios is discussed. Final cascade ion yields, spectra of cascade electrons and photons, numbers of emitted electrons and photons, and energies carried away by them are calculated. Energy acquired by the Pt atom upon photoionization is split into the following channels: a) energy stored in final cascade ions, b) energy reemitted by cascade electrons, and c) energy reemitted by cascade photons. Relative weights of these energy redistribution channels are studied. A potential of using Pt-containing agents as radiosensitizers in photon activation therapy and chemoradiation therapy of malignant tumors is discussed. Cascade-produced electrons are shown to be the main local dose depositors.
{"title":"Cascade relaxation of single K, L, M and N vacancies in atomic platinum. Ion yields and energy reemission","authors":"A.P. Chaynikov, A.G. Kochur, A.I. Dudenko","doi":"10.1016/j.elspec.2025.147554","DOIUrl":"10.1016/j.elspec.2025.147554","url":null,"abstract":"<div><div>Cascade decays of single vacancies in <em>K</em> to <em>N</em> shells of the Pt atom are studied by construction and analysis of the decay trees. Energies of cascade-produced multivacancy configurations and decay branching ratios are calculated in Pauli–Fock approximation. The role of multiplet splitting and multiplet overlapping in calculating mean transition energies and ionic configurations branching ratios is discussed. Final cascade ion yields, spectra of cascade electrons and photons, numbers of emitted electrons and photons, and energies carried away by them are calculated. Energy acquired by the Pt atom upon photoionization is split into the following channels: a) energy stored in final cascade ions, b) energy reemitted by cascade electrons, and c) energy reemitted by cascade photons. Relative weights of these energy redistribution channels are studied. A potential of using Pt-containing agents as radiosensitizers in photon activation therapy and chemoradiation therapy of malignant tumors is discussed. Cascade-produced electrons are shown to be the main local dose depositors.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"281 ","pages":"Article 147554"},"PeriodicalIF":1.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-03-10DOI: 10.1016/j.elspec.2025.147535
R.O. Kuzian , E.E. Krasovskii
Attosecond dynamics of electron reflection from a thin film is studied based on a one-dimensional jellium model. Following the Eisenbud–Wigner–Smith concept, the reflection time delay is calculated as the energy derivative of the phase of the complex reflection amplitude . For a purely elastic scattering by a jellium slab of a finite thickness the transmission probability oscillates with the momentum in the solid with a period , and closely follows these oscillations. The reflection delay averaged over an energy interval grows with , but in the limit of the amplitude becomes real, so vanishes. This picture changes substantially with the inclusion of an absorbing potential : As expected, for a sufficiently thick slab the reflection amplitude now tends to its asymptotic value for a semi-infinite crystal. Interestingly, for , around the maxima, the curve strongly deviates from , showing a narrow dip just at the maximum for . An analytical theory of this counterintuitive behavior is developed.
{"title":"Attosecond dynamics of electron scattering by an absorbing layer","authors":"R.O. Kuzian , E.E. Krasovskii","doi":"10.1016/j.elspec.2025.147535","DOIUrl":"10.1016/j.elspec.2025.147535","url":null,"abstract":"<div><div>Attosecond dynamics of electron reflection from a thin film is studied based on a one-dimensional jellium model. Following the Eisenbud–Wigner–Smith concept, the reflection time delay <span><math><mrow><mi>Δ</mi><msub><mrow><mi>τ</mi></mrow><mrow><mtext>r</mtext></mrow></msub></mrow></math></span> is calculated as the energy derivative of the phase of the complex reflection amplitude <span><math><mi>r</mi></math></span>. For a purely elastic scattering by a jellium slab of a finite thickness <span><math><mi>d</mi></math></span> the transmission probability <span><math><mi>T</mi></math></span> oscillates with the momentum <span><math><mi>K</mi></math></span> in the solid with a period <span><math><mrow><mi>π</mi><mo>/</mo><mi>d</mi></mrow></math></span>, and <span><math><mrow><mi>Δ</mi><msub><mrow><mi>τ</mi></mrow><mrow><mtext>r</mtext></mrow></msub></mrow></math></span> closely follows these oscillations. The reflection delay averaged over an energy interval grows with <span><math><mi>d</mi></math></span>, but in the limit of <span><math><mrow><mi>d</mi><mo>→</mo><mi>∞</mi></mrow></math></span> the amplitude <span><math><mi>r</mi></math></span> becomes real, so <span><math><mrow><mi>Δ</mi><msub><mrow><mi>τ</mi></mrow><mrow><mtext>r</mtext></mrow></msub></mrow></math></span> vanishes. This picture changes substantially with the inclusion of an absorbing potential <span><math><mrow><mo>−</mo><mi>i</mi><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></mrow></math></span>: As expected, for a sufficiently thick slab the reflection amplitude now tends to its asymptotic value for a semi-infinite crystal. Interestingly, for <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>≠</mo><mn>0</mn></mrow></math></span>, around the <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mi>E</mi><mo>)</mo></mrow></mrow></math></span> maxima, the <span><math><mrow><mi>Δ</mi><msub><mrow><mi>τ</mi></mrow><mrow><mtext>r</mtext></mrow></msub><mrow><mo>(</mo><mi>E</mi><mo>)</mo></mrow></mrow></math></span> curve strongly deviates from <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mi>E</mi><mo>)</mo></mrow></mrow></math></span>, showing a narrow dip just at the <span><math><mrow><mi>Δ</mi><msub><mrow><mi>τ</mi></mrow><mrow><mtext>r</mtext></mrow></msub><mrow><mo>(</mo><mi>E</mi><mo>)</mo></mrow></mrow></math></span> maximum for <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>=</mo><mn>0</mn></mrow></math></span>. An analytical theory of this counterintuitive behavior is developed.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147535"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-05-28DOI: 10.1016/j.elspec.2025.147543
Osman Murat Ozkendir
The development of high-performance cathode materials for lithium-ion batteries (LIBs) is crucial for advancing energy storage technologies. The electronic and thermal properties of lithium cuprate (Li₂CuO₂, LCO), a promising cathode material with mixed ionic and electronic conductivity were investigated. Using a two-step computational approach, Density Functional Theory (DFT) was employ to calculate the band structure and density of states (DOS) at room temperature, revealing a direct bandgap of 1.61 eV and semiconductor-like behavior. Additionally, X-ray Absorption Fine Structure (XAFS) spectroscopy utilized to probe the temperature-dependent electronic and structural dynamics of LCO, ranging from 253 K to 473 K. The results demonstrate the stability of the Cu-O blocks under elevated temperatures, highlighting their resilience during charge-discharge cycles. The Debye-Waller factor (DWF) analysis further confirms the material's moderate thermal conductivity and structural integrity, making LCO a viable candidate for high-temperature LIB applications. This comprehensive study provides valuable insights into the electronic and thermal behavior of LCO, paving the way for the design of next-generation cathode materials with enhanced electrochemical performance and thermal stability.
{"title":"Investigating the stability and conductivity of Li₂CuO₂ for high-temperature LIB applications","authors":"Osman Murat Ozkendir","doi":"10.1016/j.elspec.2025.147543","DOIUrl":"10.1016/j.elspec.2025.147543","url":null,"abstract":"<div><div>The development of high-performance cathode materials for lithium-ion batteries (LIBs) is crucial for advancing energy storage technologies. The electronic and thermal properties of lithium cuprate (Li₂CuO₂, LCO), a promising cathode material with mixed ionic and electronic conductivity were investigated. Using a two-step computational approach, Density Functional Theory (DFT) was employ to calculate the band structure and density of states (DOS) at room temperature, revealing a direct bandgap of 1.61 eV and semiconductor-like behavior. Additionally, X-ray Absorption Fine Structure (XAFS) spectroscopy utilized to probe the temperature-dependent electronic and structural dynamics of LCO, ranging from 253 K to 473 K. The results demonstrate the stability of the Cu-O blocks under elevated temperatures, highlighting their resilience during charge-discharge cycles. The Debye-Waller factor (DWF) analysis further confirms the material's moderate thermal conductivity and structural integrity, making LCO a viable candidate for high-temperature LIB applications. This comprehensive study provides valuable insights into the electronic and thermal behavior of LCO, paving the way for the design of next-generation cathode materials with enhanced electrochemical performance and thermal stability.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147543"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-03-04DOI: 10.1016/j.elspec.2025.147527
Jun Zhang , Jianhui Jin , Yujie Zhao , Jize Sun , Weifeng Wang
1,3-Butadiene is a crucial intermediate in hydrocarbon combustion and pyrolysis processes and plays a significant role as a precursor in the formation of polycyclic aromatic hydrocarbons (PAHs) and soot. This study investigates the low-pressure and high-temperature pyrolysis of 1,3-butadiene by using a newly designed silicon carbide (SiC) tubular flow microreactor, in combination with supersonic molecular beam sampling, synchrotron radiation vacuum ultraviolet single-photon ionization, and reflective time-of-flight mass spectrometry (SR-VUV-TOF-PIMS). We identified 36 pyrolysis products, ranging in mass-to-charge ratio (m/z) from 15 to 128, which included free radicals and isomeric species. The study determined the initial pyrolysis temperature of the parent compound and the initial formation temperatures of the products. Comparative analysis of our results with previous literature revealed the primary cleavage pathways in this work: 1,3-C4H6 → C2H4 + C2H2, 1,3-C4H6 → 1,2-C4H6, 1,2-C4H6 → C3H3· + CH3·, 1,3-C4H6 + C3H3· → C3H4 + C4H5·, 1,3-i-C4H5· → C4H4 + H· and 1,3-n-C4H5· → C4H4 + H·. These studies contribute valuable insights into the mechanisms of hydrocarbon combustion and pyrolysis, as well as the reference for the formation processes of PAHs and soot.
{"title":"Experimental study on low-pressure and high-temperature pyrolysis of 1, 3-butadiene using synchrotron radiation and SiC flash microreactor","authors":"Jun Zhang , Jianhui Jin , Yujie Zhao , Jize Sun , Weifeng Wang","doi":"10.1016/j.elspec.2025.147527","DOIUrl":"10.1016/j.elspec.2025.147527","url":null,"abstract":"<div><div>1,3-Butadiene is a crucial intermediate in hydrocarbon combustion and pyrolysis processes and plays a significant role as a precursor in the formation of polycyclic aromatic hydrocarbons (PAHs) and soot. This study investigates the low-pressure and high-temperature pyrolysis of 1,3-butadiene by using a newly designed silicon carbide (SiC) tubular flow microreactor, in combination with supersonic molecular beam sampling, synchrotron radiation vacuum ultraviolet single-photon ionization, and reflective time-of-flight mass spectrometry (SR-VUV-TOF-PIMS). We identified 36 pyrolysis products, ranging in mass-to-charge ratio (<em>m/z</em>) from 15 to 128, which included free radicals and isomeric species. The study determined the initial pyrolysis temperature of the parent compound and the initial formation temperatures of the products. Comparative analysis of our results with previous literature revealed the primary cleavage pathways in this work: 1,3-C<sub>4</sub>H<sub>6</sub> → C<sub>2</sub>H<sub>4</sub> + C<sub>2</sub>H<sub>2</sub>, 1,3-C<sub>4</sub>H<sub>6</sub> → 1,2-C<sub>4</sub>H<sub>6</sub>, 1,2-C<sub>4</sub>H<sub>6</sub> → C<sub>3</sub>H<sub>3</sub>· + CH<sub>3</sub>·<sub>,</sub> 1,3-C<sub>4</sub>H<sub>6</sub> + C<sub>3</sub>H<sub>3</sub>· → C<sub>3</sub>H<sub>4</sub> + C<sub>4</sub>H<sub>5</sub>·, 1,3-i-C<sub>4</sub>H<sub>5</sub>· → C<sub>4</sub>H<sub>4</sub> + H· and 1,3-n-C<sub>4</sub>H<sub>5</sub>· → C<sub>4</sub>H<sub>4</sub> + H·. These studies contribute valuable insights into the mechanisms of hydrocarbon combustion and pyrolysis, as well as the reference for the formation processes of PAHs and soot.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147527"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present experimental results on the impact energy dependence of L-subshell x-ray yields and production cross sections for the thick lead target (Pb, Z = 82) under impact of 15–30 keV electrons. Results are compared with the simulation data from the Monte Carlo Penelope code with the Distorted Wave Born Approximation (DWBA) formulations. The comparison yields fairly good agreement for the L-shell x-ray yields within the experimental uncertainties. Furthermore, the present results of the intensity ratio of and lines to the intensity of and their corresponding x-ray production cross sections are compared with available experimental and theoretical data; the agreement is found to be satisfactory. X-ray production cross sections for L-shell x-rays are derived by employing the thick target method (An et al., 2006). Furthermore, we have presented for the first time the experimental results on yield and x-ray production cross sections of the line and have compared the results with the simulation data; the agreement between two results is found to be good within the error bars of the measurements.
我们给出了在15-30 keV电子冲击下厚铅靶（Pb, Z = 82）的l -亚壳层x射线产率和产生截面的影响能量依赖的实验结果。结果与蒙特卡洛Penelope代码的模拟数据进行了比较，并采用畸变波Born近似（DWBA）公式。比较结果表明，在实验不确定度范围内，l壳层x射线产率的一致性相当好。同时，将Lβ、Lγ和Ll谱线强度与Lα谱线强度之比及其对应的x射线产生截面与已有的实验和理论数据进行了比较；协议是令人满意的。采用厚靶法推导了l壳层x射线的x射线产生截面（An et al., 2006）。此外，我们还首次给出了Ll线产率和x射线产率截面的实验结果，并将结果与模拟数据进行了比较；在测量误差范围内，两种结果的一致性较好。
{"title":"Experimental determination of L-subshells x-ray yields and production cross sections of thick lead (Z=82) element by impact of 15–30 keV electrons","authors":"Kailash Verma , Hitesh Rahangdale , Kumar Ankit Upadhayay , Raj Singh , Bhupendra Singh , Namita Yadav","doi":"10.1016/j.elspec.2025.147541","DOIUrl":"10.1016/j.elspec.2025.147541","url":null,"abstract":"<div><div>We present experimental results on the impact energy dependence of L-subshell x-ray yields and production cross sections for the thick lead target (Pb, Z = 82) under impact of 15–30 keV electrons. Results are compared with the simulation data from the Monte Carlo Penelope code with the Distorted Wave Born Approximation (DWBA) formulations. The comparison yields fairly good agreement for the L-shell x-ray yields within the experimental uncertainties. Furthermore, the present results of the intensity ratio of <span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>β</mi></mrow></msub><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>γ</mi></mrow></msub></mrow></math></span> and <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>l</mi></mrow></msub></math></span> lines to the intensity of <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> and their corresponding x-ray production cross sections are compared with available experimental and theoretical data; the agreement is found to be satisfactory. X-ray production cross sections for L-shell x-rays are derived by employing the thick target method (An et al., 2006). Furthermore, we have presented for the first time the experimental results on yield and x-ray production cross sections of the <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>l</mi></mrow></msub></math></span> line and have compared the results with the simulation data; the agreement between two results is found to be good within the error bars of the measurements.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147541"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2025-04-04DOI: 10.1016/j.elspec.2025.147538
Saki Imada , Frank M.F. de Groot
Geometry dependences of partial fluorescence yield (PFY) spectra at the L2,3-edge of 3d transition metals are discussed theoretically and experimentally for high-spin 3d5 systems in Oh and Td point symmetries. Firstly, linear polarized light's propagation direction selection rules for a two-photon process are applied to 2p3d-PFY spectroscopy. Then, the 2p3d-PFY spectra were analyzed by comparison with spectra obtained as partial integration of 2p3d-resonant inelastic X-ray scattering (RIXS) signals, utilizing the relationship between PFY and RIXS spectroscopies: the former is an integration of yield of emitted light at each excitation energy, and the latter is a dispersion of emitted light as a function of emission energy at each excitation energy. Thus, a PFY spectrum can be divided into super PFY (sPFY) spectra using partial integrations of signals on a RIXS map, such as sPFY spectra from elastic and inelastic signals. It is suggested that the origin of the large deviation of 2p3d-PFY spectral shape in a linear-horizontal geometry from a true X-ray absorption spectrum is due to the lack of elastic signals, i.e., the lack of signals emitted when the system returns to its ground state. Contrary to a 2p3d-PFY spectrum, a 2p3s-PFY spectrum is often assumed to have a one-to-one correspondence with true XAS; however, 2p3s-PFY spectroscopy is also a two-photon process that abides by the propagation direction selection rules. We will show theoretically that 2p3s-PFY spectral shapes show a geometry dependence and offer a way to obtain a true X-ray absorption structure from a combination of 2p3s-PFY spectra in linear-vertical and linear-horizontal geometries.
{"title":"Geometry-dependent analysis of 2p3d- and 2p3s-partial fluorescence yield spectra for high-spin 3d5 systems","authors":"Saki Imada , Frank M.F. de Groot","doi":"10.1016/j.elspec.2025.147538","DOIUrl":"10.1016/j.elspec.2025.147538","url":null,"abstract":"<div><div>Geometry dependences of partial fluorescence yield (PFY) spectra at the L<sub>2,3</sub>-edge of 3d transition metals are discussed theoretically and experimentally for high-spin 3d<sup>5</sup> systems in O<sub>h</sub> and T<sub>d</sub> point symmetries. Firstly, linear polarized light's propagation direction selection rules for a two-photon process are applied to 2p3d-PFY spectroscopy. Then, the 2p3d-PFY spectra were analyzed by comparison with spectra obtained as partial integration of 2p3d-resonant inelastic X-ray scattering (RIXS) signals, utilizing the relationship between PFY and RIXS spectroscopies: the former is an integration of yield of emitted light at each excitation energy, and the latter is a dispersion of emitted light as a function of emission energy at each excitation energy. Thus, a PFY spectrum can be divided into super PFY (sPFY) spectra using partial integrations of signals on a RIXS map, such as sPFY spectra from elastic and inelastic signals. It is suggested that the origin of the large deviation of 2p3d-PFY spectral shape in a linear-horizontal geometry from a true X-ray absorption spectrum is due to the lack of elastic signals, i.e., the lack of signals emitted when the system returns to its ground state. Contrary to a 2p3d-PFY spectrum, a 2p3s-PFY spectrum is often assumed to have a one-to-one correspondence with true XAS; however, 2p3s-PFY spectroscopy is also a two-photon process that abides by the propagation direction selection rules. We will show theoretically that 2p3s-PFY spectral shapes show a geometry dependence and offer a way to obtain a true X-ray absorption structure from a combination of 2p3s-PFY spectra in linear-vertical and linear-horizontal geometries.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147538"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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