Journal of Electron Spectroscopy and Related Phenomena最新文献

{"title":"Phonon effects in high-energy photoemission spectra","authors":"Takashi Fujikawa,&nbsp;Kaori Niki","doi":"10.1016/j.elspec.2025.147525","DOIUrl":"10.1016/j.elspec.2025.147525","url":null,"abstract":"<div><div>In this paper some phonon effects on high-energy photoemission spectra for solids are discussed from a theoretical point of view. In case of photoemission from deep cores, recoil and Franck–Condon (FC) effects play some important roles: The former contributes to the peak shift following classical free atom recoil shift rule, however the latter has no influence on the shift within the harmonic phonon approximation. Both contribute to the temperature dependent peak broadening. In addition to these individual effects, the interference between recoil and FC should be considered, which contributes to the peak shift. In the harmonic approximation, the recoil shift is independent of the temperature. Beyond this approximation, we can expect that the recoil shift depends on the temperature in accordance with the observed results for some special systems. In addition to the core level photoemission, we discuss the high-energy photoemission from extended valence levels: Recoil effects and the turnover from ARPES to XPS limit are discussed.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147525"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509353","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}

{"title":"Photoelectron diffraction of twisted bilayer graphene","authors":"S. Tricot ,&nbsp;H. Ikeda ,&nbsp;H.C. Tchouekem ,&nbsp;J.-C. Le Breton ,&nbsp;S. Yasuda ,&nbsp;P. Krüger ,&nbsp;P. Le Fèvre ,&nbsp;D. Sébilleau ,&nbsp;T. Jaouen ,&nbsp;P. Schieffer","doi":"10.1016/j.elspec.2025.147524","DOIUrl":"10.1016/j.elspec.2025.147524","url":null,"abstract":"<div><div>Photoelectron diffraction (PED) is a powerful spectroscopic technique that combines elemental resolution with a high sensitivity to the local atomic arrangement at crystal surfaces, thus providing unique fingerprints of selected atomic sites in matter. Stimulated by the rapid innovation in the development of various analysis methods for probing the atomic and electronic structures of van der Waals (vdW) heterostructures of two-dimensional materials, we present a theoretical assessment of the capacity of PED for extracting structural properties such as stacking, twist angles and interlayer distances. We provide a complete description of PED for the benchmark vdW heterostructure bilayer graphene (BLG), by calculating and analyzing the PED of BLG in Bernal and AA-stacking as well as twisted BLG for a wide range of the twist angle.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147524"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551406","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}

{"title":"Fine structure of spectra for secondary electron excited by electron impact – Novel spectrum data analysis and application to nearly free electron metals","authors":"Satoshi Hashimoto ,&nbsp;Tsuguo Sakurada ,&nbsp;Shigeo Tanuma ,&nbsp;Keisuke Goto ,&nbsp;Takaharu Nagatomi","doi":"10.1016/j.elspec.2025.147539","DOIUrl":"10.1016/j.elspec.2025.147539","url":null,"abstract":"<div><div>In order to analyze the fine structure of the energy distribution of secondary electrons generated through the cascade process, we measured the electron spectra of NFE metals (Li, Mg, Al, Ca, Ga, In), their compounds (Al₂O₃ and GaAs) and Fe as transition metal with a CMA-type analyzer with absolute gain. We propose that the spectrum obtained by differentiating the energy spectrum in a logarithmic representation (defined as DLS) can be used to evaluate the excitation function that generates the fine structure of the secondary electron energy distribution. We found that the fine structure of the energy distribution of secondary electrons in NFE metals is mainly due to emission through a cascade process generated by the electrons from plasmon decay, which was obtained from analyses of the DLS, the excitation function, the energy distribution of secondary electrons <em>N(E)</em>, and the EELS spectra. In addition, slow Auger electrons also generate secondary electrons through the cascade process. In Al₂O₃, a fine structure of secondary electrons was generated by electrons excited to unoccupied states by inter-band transitions and inner-shell excitation. In GaAs, both contributions from plasmon decay and electrons excited to unoccupied states by inter-band transitions and inner-shell excitation were observed. Based on these findings, it is concluded that the fine structure of the energy distribution of the secondary electrons emitted in the cascade process is due to the following electrons: 1) electrons from plasmon decay, 2) slow Auger electrons, and 3) electrons excited to unoccupied states by inter-band transitions or inner-shell excitation. These fine structures are superimposed on the structure of the individual excitation by primary electrons.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147539"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143824538","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}

{"title":"Electronic, magnetic and thermal behavior near the Invar compositions of Fe-Ni alloys","authors":"Ananya Sahoo ,&nbsp;Ayusa Aparupa Biswal ,&nbsp;S.K. Parida ,&nbsp;V.R.R. Medicherla ,&nbsp;Soumya Shephalika Behera ,&nbsp;M.N. Singh ,&nbsp;A. Sagdeo ,&nbsp;Sawani Datta ,&nbsp;Abhishek Singh ,&nbsp;Kalobaran Maiti","doi":"10.1016/j.elspec.2025.147540","DOIUrl":"10.1016/j.elspec.2025.147540","url":null,"abstract":"<div><div>The structural, magnetic and electronic properties of Fe<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Ni<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> (<span><math><mi>x</mi></math></span> = 0.32, 0.36, 0.40, 0.50) alloys have been investigated using synchrotron based x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometer and the high resolution x-ray photoelectron spectroscopy (XPS) measurements. The XRD measurement was done down to 50 K temperature. The XRD studies suggest a single phase with fcc structure for <span><math><mi>x</mi></math></span> = 0.36, 0.40, and 0.50 alloys and a mixed phase for <span><math><mi>x</mi></math></span> = 0.32 alloy containing both bcc and fcc structures. The lattice parameter of the alloys exhibits a linear dependence on temperature giving rise to a temperature independent coefficient of thermal expansion (CTE). The lowest CTE is observed for <span><math><mi>x</mi></math></span> = 0.36 Invar alloy as expected while <span><math><mi>x</mi></math></span> = 0.50 alloy exhibits the highest CTE among the alloys studied. The CTE of the fcc component of mixed phase alloy is close to that of Invar alloy. The temperature dependence of magnetization of the alloys down to 2 K reveals an overall antiferromagnetic interactions within the ferromagnetic phase causing the magnetization decreasing with lowering temperature. The field cooled and zero field cooled data show larger differences for the Invar compositions; this is also manifested in the magnetic hysteresis data at 2 K and 300 K. The Fe 2<span><math><mi>p</mi></math></span> and Ni 2<span><math><mi>p</mi></math></span> core level spectra exhibit spin–orbit split features along with a satellite feature in the Ni 2<span><math><mi>p</mi></math></span> spectra. The spectral line shapes are almost similar for all the compositions studied. Interestingly, the spin–orbit splitting for Fe 3<span><math><mi>p</mi></math></span> spectra is larger than that observed for Ni 3<span><math><mi>p</mi></math></span> suggesting additional contributions due to the exchange interaction between the Fe 3<span><math><mi>p</mi></math></span> core hole with the Fe 3<span><math><mi>d</mi></math></span> moment. This suggests large magnetic moment contribution from Fe as expected. The core level and valence band spectra, and the magnetization data suggest significant role of disorder for the Invar compositions.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"280 ","pages":"Article 147540"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870690","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}

{"title":"The effect of edge configurations diversity on the energy gap in MXene zigzag nanoribbons based on Ti3C2O2 and Sc3C2F2","authors":"M.S. Akhoundi Khezrabad ,&nbsp;O. Soltani ,&nbsp;A. Shokri","doi":"10.1016/j.elspec.2025.147526","DOIUrl":"10.1016/j.elspec.2025.147526","url":null,"abstract":"<div><div>In this study, we report the band structure and energy gap of different edges of Ti₃C₂O₂ and Sc₃C₂F₂ zigzag nanoribbons using tight-binding approximation. Our results show that in most widths of zigzag nanoribbons, the energy gap in different edge configurations has different values even though they have the same width. In Ti₃C₂O₂ nanoribbons, the presence of central atoms at the edge of the zigzag nanoribbon increases the band-gap and in Sc₃C₂F₂ nanoribbon, depending on the width of the nanoribbon, the presence of central atoms or surface atoms on the edge of the nanoribbon can increase the band-gap. The maximum difference reaches 0.3 eV in Sc₃C₂F₂ nanoribbon and 0.17 eV in Ti₃C₂O₂ nanoribbon. The band gap depending on the edge atoms can be important for the design and use of MXene nanoribbons in electronic and optoelectronic devices.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147526"},"PeriodicalIF":1.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487746","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}

{"title":"Time evolution of ion states formed during the cascade decay of vacancies produced by the electron capture decay of the 125I radionuclide","authors":"A.P. Chaynikov ,&nbsp;A.G. Kochur ,&nbsp;A.I. Dudenko","doi":"10.1016/j.elspec.2025.147522","DOIUrl":"10.1016/j.elspec.2025.147522","url":null,"abstract":"<div><div>Cascade relaxation of inner-shell vacancies in tellurium atom produced by the electron capture decay of the ¹²⁵I radionuclide is studied using Monte Carlo simulations. Final cascade ions yields and mean final ion charges upon the decay of single-inner-vacancy states Te<em>X</em>^–15<em>p</em>⁵ (<em>X</em> = 1 <em>s</em> to 5 <em>s</em>) were calculated. The time evolution of the cascade ion states is simulated, and the mean final ion charge is found to be stabilized within <em>τ</em>_casc = 10^–12 s after the electron capture decay of the ¹²⁵I nucleus. This time interval must be compared to the time <em>τ</em>_neutr needed for ions neutralization when ¹²⁵I is used as an Auger emitter in radiotherapy. Depending on the relation between <em>τ</em>_casc and <em>τ</em>_neutr, either ‘isolated-atom’ or ‘condensed-phase’ approximation should be used in theoretical descriptions of local energy deposition.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147522"},"PeriodicalIF":1.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140828","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}

{"title":"Photoionization and electronic structure of chemical warfare agents","authors":"Igor Novak","doi":"10.1016/j.elspec.2025.147523","DOIUrl":"10.1016/j.elspec.2025.147523","url":null,"abstract":"<div><div>The vertical, valence ionization energies for several chemical warfare agents (CWA): nerve agents, choking agents and blister agents have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. The calculated vertical, valence ionization energies were used to simulate UV photoelectron spectra. We also calculated 1st adiabatic ionization energies for these CWA. Our results, especially 1st ionization energies (vertical and adiabatic) may be useful when applying photoionization techniques as part of hyphenated methods for detection and identification of CWA. The variations of vertical ionization energies were rationalized by the analysis of the electronic structure of CWA. The influence of electronic structures on toxicological properties is also discussed on the basis of calculated Hirshfeld type charges.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147523"},"PeriodicalIF":1.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic dispersion of excitonic bands of the single-crystal pentacene (001) surface as measured by low-energy angle-resolved high-resolution electron energy-loss spectroscopy","authors":"Yasuo Nakayama ,&nbsp;François C. Bocquet ,&nbsp;Ryohei Tsuruta ,&nbsp;Serguei Soubatch ,&nbsp;F. Stefan Tautz","doi":"10.1016/j.elspec.2025.147514","DOIUrl":"10.1016/j.elspec.2025.147514","url":null,"abstract":"<div><div>Low-energy high-resolution electron energy-loss spectroscopy (HREELS) is a useful technique for the characterization of various excitation processes at solid surfaces. However, no successful work has been reported on molecular single-crystal samples yet. In the present study, low-energy angle-resolved HREELS measurements were conducted on single-crystal pentacene, an organic semiconductor. The results confirmed the excitonic bands exhibiting energy–momentum dispersion and anisotropy of these depending on the surface crystallographic directions, corroborating the occurrence of exciton delocalization, contrary to the ordinary notion of the Frenkel exciton for weakly interacting van der Waals molecular solids. The present results demonstrate that low-energy angle-resolved HREELS is applicable to the precise examination of the excitonic characteristics of solid-state surfaces, even for molecular semiconductor single crystals.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"279 ","pages":"Article 147514"},"PeriodicalIF":1.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Density functional theory calculations of the electronic structure and dielectric properties of metal oxide systems Al2O3, MgO, Cu2O, TiO2, WO3","authors":"Raul E. Gutierrez ,&nbsp;Ivana Matanovic ,&nbsp;Maciej P. Polak ,&nbsp;Dane Morgan ,&nbsp;Edl Schamiloglu","doi":"10.1016/j.elspec.2024.147512","DOIUrl":"10.1016/j.elspec.2024.147512","url":null,"abstract":"<div><div>Density Functional Theory is utilized to study the electronic structure and dielectric properties of various metal oxide systems (Al₂O₃, MgO, Cu₂O, TiO₂, WO₃) in comparison to their base metals (Al, Mg, Cu, Ti, and W). The properties studied include the density of states, energy band gap, Fermi energy, work function, ionization potential, and the frequency- and momentum-dependent energy loss function. This work provides high-quality first principles-calculated properties that can be further utilized in computational simulations which aim to model complicated electron inelastic scattering interactions in metal oxides and their corresponding metals. In general, properties of this nature might be of interest, but not limited, to those involved in the multipactor effect, magnetic confinement fusion, photovoltaics, charged particle accelerators, x-ray photoelectron spectroscopy, Auger electron spectroscopy, and photomultipliers.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"278 ","pages":"Article 147512"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180515","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}

{"title":"Embedding of cluster models of oxides: Implications for XPS predictions","authors":"Paul S. Bagus ,&nbsp;Connie J. Nelin","doi":"10.1016/j.elspec.2024.147511","DOIUrl":"10.1016/j.elspec.2024.147511","url":null,"abstract":"<div><div>The importance of embedding cluster models of NiO that are used to predict and analyze the Ni 2p XPS spectra in this compound is studied. The XPS obtained with an isolated NiO₆ cluster are compared with those obtained with the cluster embedded in a point charge field designed to reproduce the Madelung potential of the crystal. It is found that there is a remarkable and possibly unexpected similarity between the theoretical XPS spectra with and without point charge embedding. It is believed that this can be expected to be a general conclusion relevant for the XPS of other ionic compounds.</div></div>","PeriodicalId":15726,"journal":{"name":"Journal of Electron Spectroscopy and Related Phenomena","volume":"278 ","pages":"Article 147511"},"PeriodicalIF":1.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180514","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}