Nobuhiro Kosugi

• D.Sc.
• Professor at Osaka University

Nitrogen K-edge X-ray absorption (XA) spectroscopy of aqueous ammonia reveals a splitting in the main-edge, which through theoretical modeling is shown to be related to symmetry breaking in hydrogen bonding. The XA main-edge of NH3 is formed by a pair of degenerate core-excitations into extended molecular orbitals. In aqueous solution, these form a...

Hydrophobic cluster structures in aqueous ethanol solutions at different concentrations have been investigated by soft X-ray absorption spectroscopy (XAS). In the O K-edge XAS, we have found that hydrogen bond structures among water molecules are enhanced in the middle-concentration region by the hydrophobic interaction of the ethyl groups in ethan...

The present study aims at probing the influence of different substituents of sodium carboxylate salts R–COO⁻:Na⁺ in aqueous solutions, with R = H, CH3, C2H5, CH2Cl, CF3, and C6H5. X-ray absorption spectroscopy was used in the oxygen K-edge region to highlight the effect of R on the energy position of the O1s-to-πCOO* resonance of the carboxylate io...

Drug penetration in human skin ex vivo following a modification of skin barrier permeability is systematically investigated by scanning transmission X-ray microscopy. Element-selective excitation is used in the O 1s regime for probing quantitatively the penetration of topically applied rapamycin in different formulations with a spatial resolution r...

Glyoxal (CHOCHO) and methylglyoxal (CH3C(O)CHO) are well-known components of atmospheric particles and their properties can impact atmospheric chemistry and cloud formation. To get information on their hydration states in aqueous solutions and how they are affected by the addition of inorganic salts (sodium chloride (NaCl) and sodium sulfate (Na2SO...

Ge atoms segregating on zirconium diboride thin films grown on Ge(111) were found to crystallize into a two-dimensional bitriangular structure, which was recently predicted to be a flat band material through an embedded kagome lattice. Angle-resolved photoelectron emission experiments together with theoretical calculations pointed out the existence...

We have designed a new low-pass Fresnel zone plate (LPFZP) to extend soft x-ray absorption spectroscopy (XAS) to the lithium K absorption edge in a scanning transmission x-ray microscope (STXM). The performance of the LPFZP was evaluated in the STXM beamline at the UVSOR-III Synchrotron (Okazaki, Japan); the contribution of the higher-order harmoni...

The interaction of an ion with surrounding solvent molecules is revealed by X-ray absorption spectroscopy in transmission mode for the case of calcium dication dissolved in pure water, methanol and ethanol at the Ca K and L2,3-edges. The near-threshold K-shell excitation leads to two distinct solvent-dependent features, the Ca 1 s to 3d and 4p elec...

An array of ZnO/Fe2O3 core-shell nanowires (NW) for the highly efficient absorption of light and carrier collection is developed for use in photoelectrochemical (PEC) water-splitting. The oriented NW architecture favors physical matching, providing a direct electron conduction pathway and reducing the diffusion length of photogenerated holes. This...

Glyoxal (CHOCHO) and methylglyoxal (CH3C(O)CHO) are well-known components of atmospheric particles and their properties can impact atmospheric chemistry and cloud formation. To get information on their hydration states in aqueous solutions and how they are affected by addition of inorganic salts (sodium chloride (NaCl) and sodium sulfate (Na2SO4)),...

Ge atoms segregating on zirconium diboride thin films grown on Ge(111) were found to crystallize into a two-dimensional bitriangular structure which was recently predicted to be a flat band material. Angle-resolved photoemission experiments together with theoretical calculations verified the existence of a nearly flat band in spite of non-negligibl...

Two-dimensional angle-resolved photoelectron spectroscopy is a powerful method to study the electronic structure of a crystal surface. The latest version of the angle-resolved photoelectron spectroscopy analyzer was installed at the BL6U of the UVSOR-III Synchrotron. This spectrometer consists of a hemispherical electron analyzer equipped with a me...

Chemical processes in solution are influenced with microheterogeneity (MH), where two liquids seem to be mixed in a macroscopic scale but are microscopically inhomogeneous. We have investigated one of the simplest MH systems, aqueous acetonitrile solution, by using soft X-ray absorption spectroscopy (XAS). Molecular interactions of acetonitrile wer...

We report on attosecond transient absorption spectroscopy of NO and N2O molecules at the N K-edge (400 eV). We discuss the sub-optical-cycle electronic dynamics in these molecules during the strong-field ionization process.

Photoinduced quantum dynamics in molecules have hierarchical temporal structures with different energy scales that are associated with electron and nuclear motions. Femtosecond-to-attosecond transient absorption spectroscopy (TAS) using high-harmonic generation (HHG) with a photon energy below 300 eV has been a powerful tool to observe such electro...

Soft X-ray absorption spectroscopy (XAS) involving excitation processes of a core electron to unoccupied states is an effective method to study local structures around excited C, N, and O atoms in liquid samples. Since soft X-rays are strongly absorbed by air and liquid itself, we have developed transmission-type liquid flow cells, where the absorb...

The application of soft X-ray absorption spectroscopy (XAS) to liquid cells based on microfluidics for chemical state analysis of light elements is much more difficult than hard X-ray absorption since soft X-rays cannot deeply penetrate a microfluidic cell. In this study, we have newly developed a microfluidic cell for spatially resolved XAS, where...

We have developed an acceptance-cone-tunable (ACT) electron spectrometer for the highly efficient constant-energy photoelectron mapping of functional materials. The ACT spectrometer consists of the hemispherical deflection analyzer with the mesh-type electrostatic lens near the sample. The photoelectron trajectory can be converged by applying a neg...

Photoinduced quantum dynamics in molecules have hierarchical temporal structures with entangled electronic and nuclear motions. Femtosecond-to-attosecond transient absorption spectroscopy (TAS) using high-harmonic generation (HHG) in the extreme ultraviolet region with a photon energy below 100 eV has been a powerful method for observing such dynam...

Organic-inorganic hybrid films were fabricated from cellulose nanofibrils (CNF) and nanosilica (5–30% wt) embedded in a chitosan (Chi) biopolymer matrix using a slow evaporation method. The self-standing films exhibited high strength and modulus up to 120 ± 5 MPa and 7.5 ± 0.4 GPa, respectively, which are remarkably high values for biopolymer/chito...

The photoelectron angular distribution of organic thin films is essential in discussion of the (opto)electronic properties from the viewpoints of the spatial distribution of molecular orbitals and the interaction of molecular electronic states. We discuss the role of the weak intermolecular interaction in highly-ordered aromatic molecules on the ph...

Benzene is the simplest aromatic molecule with intermolecular π-π interactions. Since ordered liquids are key structures to study chemical and biological phenomena in the liquid state, ordered structures of benzene confined in nanopores have been extensively studied, whereas those in the liquid state are still unknown. In this study, we address fun...

STXM Chemical Mapping of Norway Spruce Knotwood Lignans - Volume 24 Supplement - Marko Huttula, Minna Patanen, Riikka Piispanen, Takuji Ohigashi, Nobuhiro Kosugi, Sufal Swaraj, Rachid Belkhou, Andrey Pranovich, Tuula Jyske, Petri Kilpelainen, Anna Karkonen, Risto Korpinen, Tapio Laakso, Sauli Valkonen, Pekka Saranpaa

Probing the Electronic Structure of BiVO4 Coated ZnO Nanodendrite Core- Shell Nanocomposite Using X-ray Spectroscopic and Spatially Resolved Scanning Transmission X-ray Microscopy Studies - Volume 24 Supplement - Mandar M. Shirolkar, Yu-Fu Wang, Yu Cheng Shao, Kuan-Hung Chen, Hsiao-Tsu Wang, Xian-Sheng Qiu, Jih-Sheng Yang, Jih-Jen Wu, Jau-Wern Chio...

3-Dimensional Chemical Structures of an Isolated Cell Nucleus by a Scanning Transmission X-ray Microscope - Volume 24 Supplement - Takuji Ohigashi, Atsushi Ito, Kunio Shinohara, Shigenobu Tone, Yuichi Inagaki, Hayato Yuzawa, Nobuhiro Kosugi

Mapping Highly Efficient Mixed-cation Pseudohalide-perovskite Solar Cells with a Scanning Transmission X-ray Microscope - Volume 24 Supplement - Ming-Wei Lin, Hung-Wei Shiu, Kuo-Chin Wang, Ming-Hsien Li, Yu-Ling Lai, Takuji Ohigashi, Nobuhiro Kosugi, Tzung-Fang Guo, Peter Chen, Yao-Jane Hsu

The fabrication of multidimensional organometallic halide perovskite via a low‐pressure vapor‐assisted solution process is demonstrated for the first time. Phenyl ethyl‐ammonium iodide (PEAI)‐doped lead iodide (PbI2) is first spin‐coated onto the substrate and subsequently reacts with methyl‐ammonium iodide (MAI) vapor in a low‐pressure heating ove...

Various synchrotron radiation-based spectroscopic and microscopic techniques are used to elucidate the room-temperature ferromagnetism of carbon-doped ZnO-nanowires (ZnO-C:NW) via a mild C+ ion implantation method. The photoluminescence and magnetic hysteresis loops reveal that the implantation of C reduces the number of intrinsic surface defects a...

Intermolecular interactions of pyridine in liquid and in aqueous solution are studied by using soft X-ray absorption spectroscopy (XAS) at the C, N, and O K-edges. XAS of liquid pyridine shows that the N 1s→π* peak is blue shifted and the C 1s→π* peak of the meta and para sites is red shifted, respectively, as compared with XAS of pyridine gas. The...

The orbital-specific interfacial and intermolecular interactions in crystalline films of iron phthalocyanine (FePc) grown on an Au(111) surface were studied by means of angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. The temperature-dependent ARPES measurement on the FePc monolayer reveals the formation of the molecule...

A series of polymerized high internal phase emulsion (polyHIPE) materials have been prepared by using a water in oil emulsion stabilized by a macro-RAFT agent acting as a polymeric surfactant, 2-(butylthiocarbonothioylthio)-2-poly(styrene)-b-poly(acrylic acid). The pore structure of formed polyHIPEs were closed. By removing the RAFT-end group of th...

Interaction between water molecules and alkali metal ions in aqueous salt solutions has been studied by the oxygen K-edge soft X-ray absorption spectroscopy (XAS) in transmission mode. In the measurement of several alkali halide aqueous solutions with different alkali chlorides (Li, Na, and K) and different sodium halides (Cl, Br, and I), the pre-e...

The electronic structure of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-TCNQ (F4TCNQ) monolayers on Au(111) has been investigated by means of angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. In contrast to the physisorbed TCNQ/Au(111) interface, the high-resolution core-level photoemission spectra an...

Recently, hydrogen production system by electrochemical water splitting has received attractive attention to realize a sustainable society that does not depend on fossil fuels. For commercial applications, the improvement of overall water splitting efficiency has been required by the development of highly active oxygen evolution electrocatalyst. In...

High-resolution resonant inelastic x-ray scattering (RIXS) and low-energy photoemission spectra of oxygen molecules have been measured for investigating the electronic structure of Rydberg states in the O 1s → σ∗ energy region. The electronic characteristics of each Rydberg state have been successfully observed, and new assignments are made for sev...

A sample cell for performing computed tomography (CT) was developed. The 3-dimensional (3D) structure of polystyrene spheres was observed and the fluctuation of reconstructed linear absorption coefficients (LAC) was 9.3%. To improve the quality of data in 3D spectro-microscopy, required measurement condition is discussed.

In soft X-ray absorption spectroscopy in transmission mode (T-mode XAS), it is necessary to optimize the thickness of thin liquid layers for appropriate absorbance around 0.3-0.7 and keep the sample thickness flat within a photon beam. In the present work at the UVSOR Synchrotron Facility, a thin liquid layer is sandwiched between two 100 nm thick...

In-situ/operando techniques have been developed for spectromicroscopic studies of heavy elements using hard X-rays with high transmittance in samples and long focal length of optical elements (i.e., long working distance) at photon energies >4 keV. On the other hand, in-situ measurements in the soft X-ray region for spectromicroscopic studies of li...

Nanodiamonds exhibit exceptional colloidal properties in aqueous media which lead to a wide range of applications in nanomedicine and other fields. Nevertheless, the role of surface chemistry on the hydration of nanodiamonds remains poorly understood. Here we probed the water hydrogen bond network in aqueous dispersions of nanodiamonds by infrared,...

The move toward sustainable hydrogen production from water using renewable energy, a highly efficient oxygen evolution electrocatalyst, is crucial because watersplitting efficiency is restricted to the oxygen evolution capability, which is insufficient compared to the hydrogen evolution reaction. Herein, we report a new method that improves the oxy...

Recent technical developments of X-ray absorption spectroscopy (XAS) enable us to measure in situ/operando transmission spectra of liquid samples in the soft X-ray region. We have discussed how various inter-molecular interactions around the core-excited atom are analyzed from the chemical shifts in XAS for the chemical state analysis of interactin...

In order to discuss the site specificity in the organic/metal interfacial interaction, the electronic structure of the well-ordered interface of cobalt phthalocyanine (CoPc) adsorbed on Au(111) is studied by angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. The core-level and valence-band ARPES spectra show an evidence f...

Photoelectrochemical water splitting using solar energy is an attractive candidate to produce hydrogen gas from water. This system consists of two half reactions of hydrogen and oxygen evolutions. Among them, the rate of oxygen evolution is generally slower than that of hydrogen evolution. Thus, the development of efficient oxygen evolution catalys...

Label-free detection of core-multishell (CMS) nanocarriers and the anti-inflammatory drug dexamethasone is reported. Selective excitation by tunable soft X-rays in the O 1s-regime is used for probing either the CMS nanocarrier or the drug. Furthermore, the drug loading efficiency into CMS nanocarriers is determined by X-ray spectroscopy. The drug-l...

Research of blood substitute formulations and their base materials is of high scientific interest. Especially fluorinated microemulsions based on perfluorocarbons, with their interesting chemical properties, offer opportunities for applications in biomedicine and physical chemistry. In this work, carbon K-edge absorption spectra of liquid perfluoro...

An azimuthal rotatable sample cell, an electrochemical cell and a controlled humidity cell for in-situ scanning transmission X-ray microscopy (STXM) were developed at UVSOR-III Synchrotron (Okazaki, Japan). By using these sample cells, the polarization dependence of sodium titanate nanoribbons, in-situ electrochemistry of 0.1M FeSO4 solution, and i...

Organometal-trihalide-perovskite-based solar cells have exhibited high efficiencies when incorporated into mesoscopic NiO (NiOnc) hole-transport layers. The integration of a NiOnc-perovskite heterojunction provides an inorganic alternative as a p-type contact material with efficient hole extraction for perovskite-based solar cells. Herein the origi...

Here we present an overview of recent developments of X-ray and electron spectroscopy to probe water at different temperatures. Photon-induced ionization followed by detection of electrons from either the O 1s level or the valence band is the basis of photoelectron spectroscopy. Excitation between the O 1s and the unoccupied states or occupied stat...

A whole A549 cell and isolated nuclei of HeLa S3 cells in the apoptotic process were investigated by using a scanning transmission X-ray microscope (STXM) in the UVSOR Synchrotron (Okazaki, Japan). Near edge X-ray absorption fine structures(NEXAFS) of DNA and histone in the N K-edge region were measured as reference and their distribution in the nu...

In the version of this Letter originally published the state with Emin = 23 eV was mislabelled throughout and should have been labelled 12ϕg. This has been corrected in the online versions 19 November 2015.

This investigation studies the various magnetic behaviors of graphene oxide (GO) and reduced graphene oxides (rGOs) and elucidates the relationship between the chemical states that involve defects therein and their magnetic behaviors in GO sheets. Magnetic hysteresis loop reveals that the GO is ferromagnetic whereas photo-thermal moderately reduced...

A superlattice of strained Au-Si atomic wires is successfully fabricated on a Si surface. Au atoms are known to incorporate into the stepped Si(111) surface to form a Au-Si atomic wire array with both one-dimensional (1D) metallic and antiferromagnetic atomic chains. At a properly reduced density of Au, we find a regular array of Au-Si wires in alt...

The structure of interfacial water layers around nanoparticles dispersed in an aqueous environment may have a significant impact on their reactivity and on their interaction with biological species. Using transmission soft X-ray absorption spectroscopy in liquid, we demonstrate that the unoccupied electronic states of oxygen atoms from water molecu...

In situ O K-edge X-ray absorption fine structure (XAFS) spectroscopy was applied to investigate the electronic and structural change in the nickel–borate (Ni–Bi) electrocatalyst during the oxygen evolution reaction (OER). An absorption peak was observed around 528.7 eV at 1.0 V versus Ag/AgCl in a potassium borate aqueous solution, which relates wi...

Perfluorocarbons are a family of molecules consisting mainly of carbon and fluorine atoms. They have interesting chemical properties and have diverse applications in biomedicine, physical chemistry and polymer science. In this work, Carbon K-edge absorption and emission spectra of liquid decalin are presented and compared to perfluorodecalin. A com...

In this review, we have demonstrated several applications of newly-developed in situ/operando liquid flow cells for the transmission XAS (X-ray absorption spectroscopy) measurement in the soft X-ray undulator beamline BL3U dedicated to the chemical application of UVSOR-III Synchrotron. The liquid layer is sandwiched between two thin membranes and i...

Selective probing of dexamethasone in excised human skin using soft X-ray spectromicroscopy provides quantitative concentration profiles as well as two dimensional drug distribution maps. Element- and site-selective excitation of dexamethasone at the oxygen K-edge and the lateral step width adjusted to 1 μm provides detailed information on the loca...

Functionalities of organic semiconductors are governed not only by individual properties of constituent molecules but also by electronic states near the Fermi level such as frontier molecular orbitals, depending on weak intermolecular interactions in various conformations. The individual molecular property has been widely investigated in detail; on...

In conventional in situ spectroscopies of solid-liquid heterogeneous catalytic reactions, it is difficult to measure the conversion of liquid substrates on solid catalysts, due to the lack of sensitivity and the difficulty in separation of target signals in the mixture of substrates, reactants, products, solvents, and solid catalysts. Element-speci...

For a better understanding of the electrochemical reaction, it is necessary to investigate the local structures of electrolytes, including solid-liquid interfaces at different potentials. X-ray absorption spectroscopy (XAS) is an element-specific method to investigate the local structures of a liquid. Recently, we developed a transmission-type liqu...

The valence band structure of α-phase crystalline films of cobalt phthalocyanine (CoPc) grown on Au(111) is investigated by using angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. The photo-induced change in the ARPES peaks is noticed in shape and energy of the highest occupied molecular orbital (HOMO, C 2p) and HOMO-1 (...

In order to investigate local structures of electrolytes in electrochemical reactions under the same scan rate as a typical value 100 mV/s in cyclic voltammetry (CV), we have developed an in operando observation system for electrochemical reactions by soft X-ray absorption spectroscopy (XAS) with a potential modulation method. XAS spectra of electr...

Efforts have been made to elucidate the origin of d(0) magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defec...

Liquid methanol shows one- and two-dimensional (1D/2D) hydrogen bond (HB) networks and liquid water shows three-dimensional (3D) HB networks. We have clearly found three different local structures around the methyl group of methanol-water binary solutions (CH3OH)X(H2O)1-X at different concentrations in C K-edge soft X-ray absorption spectroscopy (X...

Variable size neon clusters consisting mostly of surface sites are investigated in the Ne 2s regime (44-50 eV), which is characterized by Rydberg-/exciton transitions. Distinct changes in peak shape are observed upon the transition from the atom to clusters as probed by yields of mass selected cations and threshold photoelectron spectra, where chan...

Construction of a scanning transmission x-ray microscope (STXM) beamline is in progress at UVSOR (Okazaki, Japan). To obtain high brilliance with high resolving power for the incident x-rays, the combination of an in-vacuum undulator and a Monk-Gillieson mounting monochromator with a varied line spacing plane grating was adopted. Resolving power, s...

Polarization-dependent resonant inelastic x-ray scattering is demonstrated here for liquid acetonitrile, acetone and dimethyl sulfoxide, using the liquid micro-jet technique. Selective excitation to an unoccupied orbital with a specific symmetry at the K-edge x-ray absorption of liquid samples determines the polarization-dependent emission of the o...

We reveal quite small but different intermolecular valence band dispersions of sub-100-meV scale in crystalline films of Zn and Mn phthalocyanine (ZnPc and MnPc) and fluorinated ZnPc (F_{16}ZnPc). The intermolecular transfer integrals are found to be reasonably dependent on the intermolecular distance with the 75±5 meV/Å relation. Furthermore, the...

A high-resolution soft X-ray emission spectrometer has been developed for site-specific electronic structure analysis of functional materials in the photon energy range of 50-600 eV on the in-vacuum undulator beamline BL3U of the UVSOR facility. In order to realize the high detection efficiency without sacrificing the energy resolution to the signa...

Change in valence of Fe ions in aqueous iron sulfate solutions at different potentials has been studied by Fe L-edge soft X-ray absorption spectroscopy (XAS) in transmission mode. Each XAS spectrum is measured at a constant potential by using a liquid cell with built-in electrodes. A nonlinear oxidation of Fe(II) ions to Fe(III) ions is observed wh...

Carbon nanotube (CNT)/n-type SiC heterojunctions were formed by surface decomposition of 6H-SiC(0001), where each CNT directly bonded to SiC crystal at the interface without any interlayer. Through heating temperature and heating time, the CNT length could be controlled up to 4 mu m. For the sample with CNTs of 180 and 230 nm in thickness, distinct...

This paper reports an advanced study of the excited ionic states of the gas-phase nitrogen molecule in the binding-energy region of 22–34 eV, combining ultrahigh-resolution resonant photoemission (RPE) and ab initio configuration-interaction calculations. The RPE spectra are recorded for nine photon energies within the N 1s→π* absorption resonance...

We investigated Pt-induced nanowires on the Si(110) surface using scanning tunneling microscopy (STM) and angle-resolved photoemission (ARP). High resolution STM images show a well-ordered nanowire array of 1.6 nm width and 2.7 nm separation. ARP reveals fully occupied one dimensional (1D) bands with a Rashba-type split dispersion. Local dI/dV spec...

The structures of mixed argon-nitrogen clusters of different compositions are investigated by analyzing core level shifts and relative intensities of surface and bulk sites in the Ar 2p(3∕2) regime in soft X-ray photoelectron spectroscopy. These structures are confirmed by core level shift calculations taking induced dipole interactions into accoun...

The correlation between the p-type hole conduction and the electronic structures of Cr-deficient CuCr1−xO2 (x=0−0.1) compounds was investigated using O K-, Cu, and Cr L3,2-edge x-ray absorption near-edge structure (XANES), scanning photoelectron microscopy, and x-ray emission spectroscopy measurements. XANES spectra reveal a gradual increase in the...

Born–Oppenheimer and Franck–Condon approximations are two major concepts in the interpretation of electronic excitations and modeling of spectroscopic data in the gas and condensed phases. We report large variations of the anisotropy parameter (β) for the fully resolved vibrational sub-states of the X2Πg electronic ground state of O+2 populated by...

The electronic structure of the unoccupied and occupied states of potassium (K)-doped and undoped picene crystalline films has been investigated by using the element-selective and bulk-sensitive photon-detection methods of X-ray absorption and emission spectroscopies. We observed the formation of the doping-induced unoccupied and occupied electroni...

The polar character of the sulfinyl bond, which determines many of the properties of dimethyl sulfoxide (DMSO), is a result of charge transfer in low-lying π-type orbitals. This characteristic-together with the wide energy gap between the highest occupied and the lowest unoccupied molecular orbitals of this substance-makes DMSO a relatively inert a...

Energy band alignment at the interface between carbon nanotubes (CNTs) and n-type 6H-SiC formed by the surface decomposition of SiC was investigated using high-resolution photoelectron spectroscopy (PES). Valence band spectra of the CNT films showed a Fermi edge, indicating metallic character. PES results revealed that a Schottky barrier was formed...

This study investigates the strong photoluminescence (PL) and x-ray excited optical luminescence observed in nitrogen-functionalized two dimensional graphene nano-flakes (GNFs:N), which arise from the significantly enhanced density of states in the region of Π states and the gap between Π and Π* states. The increase in the number of the sp2 cluster...

Structures of small mixed krypton-xenon clusters of different compositions with an average size of 30-37 atoms are investigated. The Kr 3d(5/2) and Xe 4d(5/2) surface core level shifts and photoelectron intensities originating from corner, edge, and face/bulk sites are analyzed by using soft x-ray photoelectron spectroscopy. Structural models are d...

Rydberg-valence (RV) mixing and doublet-quartet (DQ) interchannel coupling in the core-excited states of triplet open-shell O2 are experimentally and theoretically unveiled through the resonant inelastic x-ray scattering around the O 1s→σu* resonance. Ab initio calculations explain complicated excitation energy dependence of the spectral profile by...

Electron-density distributions and potential-energy surfaces are important for predicting the physical properties and chem- ical reactivity of molecular systems. Whereas angle-resolved photoelectron spectroscopy enables the reconstruction of molecular-orbital densities of condensed species1 , absorption or traditional photoelectron spectroscopy are...

The gas-to-solid shift of benzene is reported in the C 1s-core level regime, where the C 1s → π*-transition is investigated between 284.0 eV and 286.5 eV. Simultaneous experiments on the gas phase and condensed species are used to determine the gas-to-solid shift within an accuracy of ±5 meV. Specifically, it is observed that the vibrationally reso...

Introduction Angle-Resolved Photoion-Yield Spectroscopy ARPIS of N2 ARPIS of C2H2 ARPIS of O2 ARPIS of SO2 Some Extensions Related to ARPIS Technique Acknowledgments References

In situ element-specific observation of electronic states of organic films beneath metal electrodes is achieved by x-ray absorption spectroscopy (XAS) in the bulk-sensitive fluorescence-yield (FY) mode. The molecular orientation in Au-covered oligo-thiophene films is confirmed by the C K-edge FY-XAS spectra and the applied bias dependence of the sp...

The local electronic structures of crystalline and amorphous films of zinc phthalocyanine (ZnPc) and metal-free phthalocyanine (H(2)Pc) have been studied by soft x-ray emission spectroscopy (XES). We found a clear crystalline structure dependence of the elastic-peak shape in the resonant XES spectra. The elastic peaks of both ZnPc and H(2)Pc are fo...