A recent muon spin rotation (μ⁺SR) study on a paramagnetic defect complex formed upon implantation of μ⁺ pseudo-proton into SrTiO₃ is reviewed with a specific focus on the relation with experimental signatures of coexisting delocalized and localized electrons in hydrogen-irradiated metallic SrTiO₃ films. The paramagnetic defect complex, composed of interstitial μ⁺ and Ti³⁺ small polaron, is characterized by a small dissociation energy of about 30 meV. Density functional theory (DFT) calculations in the generalized gradient approximation (GGA) + U scheme for a corresponding hydrogen defect complex reveal that a thermodynamic donor level associated with electron transfer from an H⁺—Ti³⁺ complex to the conduction band can form just below the conduction band minimum for realistic U values. These findings suggest that the coexistence of delocalized and localized electrons can be realized in hydrogen-irradiated SrTiO₃ in electron-rich conditions.

A novel X-ray absorption spectroscopy technique in the soft X-ray region has been developed, which enables the real-time observation of surface chemical reactions under near ambient pressures by sequentially recording the absorption spectra without scanning the photon energy of the incident X-rays. The wavelength-dispersed soft X-rays, in which the wavelength (energy) continuously changes as a function of position, illuminate the sample, and the fluorescence soft X-rays emitted at different position on the sample are separately corrected by an imaging optics consisting of two spherical mirrors. By using the developed system, a series of X-ray absorption spectra was recorded during the oxidation reaction of copper surface under air pressure of up to 5000 Pa at a data acquisition time of 10 s for each spectrum. The curve-fitting analysis for the recorded spectra indicates that only the CuO species increases with 500 Pa air, while Cu₂O appears at 5000 Pa.

Graphene is attracting vast interest due to its superior electronic and mechanical properties. However, structure and electronic properties of its edge are often neglected, although they are important for nanoscale devices because the edge ratio becomes larger by decreasing the device size. In this study, we suggest a way to fabricate a graphene with atomically aligned zigzag edges by applying hydrogen-plasma etching (HPE) technique. By patterning a graphene prior to HPE, it is succeeded to shape a graphene in desired structure. Both atomic force microscopy and Raman spectroscopy confirm that the graphene shaped by this technique preserves its honeycomb structure even on the edge, which is aligned with zigzag structure. Although the mechanism of the anisotropic etching by hydrogen-plasma have not been clarified yet, the sample position dependence of the etching rate suggests that the hydrogen-radicals are responsible for the anisotropic etching.

Acicular crystal growth of phthalocyanine derivative with eight octyl group has been studied. The observation by scanning tunneling microscopy showed seed crystals grown on graphite substrate and scanning electron microscope image showed rod-like structure, both of which have been confirmed by transmission electron microscopy. The X-ray diffraction pattern showed two peaks and a broad peak, attributed to c-axis stacking and long aliphatic chains randomly arranged in the columnar mesophase.

The aluminum oxide thin films formed on the surfaces of FeCo-V alloys doped with a small amount of aluminum were characterized by ellipsometry and electrical resistivity measurements. Aluminum oxide films on alloy surfaces were selectively formed by annealing under a low partial pressure of oxygen. The thickness of the oxide films increased with increasing aluminum content and temperature. However, the electrical resistivity of the oxide thin films did not correlate with the thickness of the oxide films. To clarify the anomaly of the resistivity, micro-beam X-ray photoelectron spectroscopy (XPS) was used to characterize the two-dimensional distribution of elements on the alloy surface. The XPS results show that the oxide films were partially exfoliated in the alloys with a high aluminum content. In particular, the oxide films were likely to be exfoliated or separated in relatively thick oxide films because of their dissimilar properties at vicinities close to the interface between the substrate and aluminum oxide thin films. Therefore, the thickness of the oxide film, and the amount of aluminum, are crucial for controlling the formation of aluminum oxide thin films with high resistivity in FeCo-V alloys.

Generally, focused ion beams are generated via the ionization process of liquid metal ion sources (LMISs); the LMIS components are made from pure liquid metals or alloys. Because of high operating cost associated with LMISs, suitable alternatives for a low-cost ion beam source must be explored. In this study, a Co nitrate solution containing ethanol and 2-(2-butoxyethoxy) ethanol solvent was prepared to form an ion source containing metallic ions. The Co-contained ion beams are generated through a vacuum electrospray method. I estimated the mass-controlled ion beams using rotating electric field mass analyzers (REFMS). I focused on three mass-controlling states at typical frequencies (300, 350, and 400 kHz). The distributions of the Co image indicate the successful generation of a mass-controlled ion beam. This mass-controlling system will allow for elemental-driven fabrication processs governed by the periodic law via REFMS.

Aromatic polyamide (PA)-silica (SiO₂) composite particles were synthesized incorporating a silane coupling agent (SCA) at two different concentrations or without the SCA, using a mixture of acetone and N,N-dimethylacetamide. The three types of composite particles were macroscopically similar to the original silica particles in terms of size and morphology. The extent to which the SiO₂ particles were coated with the SCA was found to be dependent on the concentration of the SCA used in the synthesis. However, all particles had almost the same level of PA coating regardless of the amount of SCA added. These coatings decreased the total pore volume and the surface area of the porous SiO₂ particles while maintaining the original porous structure. Adsorption capacity tests using rhodamine B in water showed that all PA-coated particles removed 73 to 84% of the dye while untreated particles or those coated with only the SCA adsorbed from 14 to 21%. This significant difference demonstrated the beneficial effect of the PA. Thus, composite particles with significant dye adsorption efficiencies could be obtained without the SCA treatment.

We investigated the annealing behavior of hydrogen in a high-dose hydrocarbon-molecular-ion-implanted silicon during rapid thermal annealing (RTA). Gettering sinks in the high-dose hydrocarbon-molecular-ion-implanted region are formed not only at carbon-related defects but also at defects related to the amorphous layer after RTA. The concentration of hydrogen trapped by the defects was analyzed by secondary ion mass spectrometry (SIMS). As a result, the concentration of hydrogen trapped by the amorphous-related defects was found to be higher than that of hydrogen trapped by carbon-related defects with increasing temperature. The dissociation activation energy of trapped hydrogen at each type of defect was estimated using the consecutive reaction model. The dissociation energies at amorphous-related and carbon-related defects are 0.94 ± 0.22 and 0.67 ± 0.12 eV, respectively. The hydrogen trapped in the amorphous-related defects is considered to be in a bonding state with multivacancies, such as H₂–V₆. On the other hand, its bonding state in the carbon-related defects is assumed to be C–H₂ in carbon and self-interstitial silicon (C_s–I) clusters and H₂–V in tetrahedral (T_d) sites. Therefore, a high gettering capability of hydrogen can be expected by forming the amorphous-related defects peculiar to the high-dose implantation conditions.

Information of spatial and energy distribution of the electronic state described from the localized molecular orbitals is important to understand the electronic and optical properties of molecular materials. In this study, photoemission spectra of a highly-oriented-coronene monolayer on Au(111) were measured by a photoelectron momentum microscope (PMM) installed at the soft X-ray beamline BL6U of UVSOR-III synchrotron. Whole valence band mapping across wide momentum space and site-selective resonant photoemission spectroscopy of this system were demonstrated as a case study of the newly installed PMM apparatus.

The suppression of the charging effect for powder and plate-shape insulating materials in hard X-ray photoelectron spectroscopy (HAXPES) was investigated. For Cr₂O₃ powder materials, a method of mixed conductive powder materials such as multi-walled carbon nanotube or colloidal graphite resulted in an improvement of the shifts of the photoelectron spectra to more proper positions and the lower peak widths compared with the untreated Cr₂O₃ powder. For a method of a conductive thin film coated on a MgO substrate, we found that a 2-nm thick Os film worked effectively to suppress the charging effect. We concluded that these methods provide a practical control for the charging effect in HAXPES measurements.

We investigated the effect of annealing on the depth concentration profile of the fullerene C₆₀ material exposed to Cs or CsI vapor, as a potential absorber of Cs-135 by angle-resolved X-ray photoelectron spectroscopy. The effects of mild annealing at around 200°C, vapor dosing under heating at around 200°C, and the characteristic desorption behavior that occurs at higher temperatures were investigated. It was found that, after annealing at 280°C or higher, Cs remains in the C₆₀ films whereas CsI is de sorbed.