We applied a momentum-selected photoelectron emission microscopy (PEEM) approach to image crystallographic domains in metallic thin films, even in the absence of chemical or work-function contrast. The method was employed to epitaxial Ir(111) films (∼60 nm) grown on sapphire(0001) by molecular beam epitaxy (MBE) using a two-step temperature protocol followed by hydrogen annealing, which yielded high crystalline quality. X-ray diffraction confirmed the (111) orientation and the presence of twinning, and rocking-curve analysis revealed a sharp component with a full width at half maximum of 0.06°, reflecting high near-surface crystallinity. Atomic force microscopy showed a low surface roughness of ∼0.3 nm. Local momentum-resolved photoelectron spectroscopy using the photoelectron momentum microscope with a 5-µm field of view revealed large crystal domains with a single crystallographic orientation, extending over area of several hundred µm2. In addition, crystallographic symmetry yields mirror-symmetric momentum patterns for twin domains. Placing a contrast aperture at a selected point in momentum space and then switching to PEEM mode, we obtained complementary real-space images that resolve twin domains and their ∼120° linear boundaries—features that have been difficult to resolve with conventional PEEM owing to the negligible work-function contrast. Our results demonstrate that MBE-grown Ir(111) thin films exhibit high quality, approaching that of bulk Ir, and that we have established a growth method to achieve such films. Furthermore, the momentum-selected PEEM we used in this work provides a straightforward route to correlate reciprocal-space symmetry with real-space mapping of twin-domain structures in face-centered cubic metals.

The 10th International Symposium on Surface Science (ISSS-10)—Innovations for a Better Society—, which was organized by The Japan Society of Vacuum and Surface Science (JVSS), Public Interest Incorporation Association, took place at Kitakyushu International Conference Center, Kitakyushu City, Fukuoka Prefecture, from October 20 to 24, 2024. On behalf of the ISSS-10 organization committee, I am pleased to present this collection of papers originally presented in ISSS-10. Scope of ISSS-10 included seven basic sessions: Surface Structures and Characterization; Physics at Surfaces and Interfaces; Nanotechnology and Nanomaterials; Surface Chemistry and Dynamics; Environmental and Energy Applications; Soft/Bio Material Interfaces; Vacuum Technology and Surface Engineering; and three focused sessions: Carbon Neutral, 2D Materials and Beyond, AI and Informatics.

Liquid-crystalline (LC) nitroxide radicals (NRs) with spin 1/2, localized in each mesogen core, exhibit anisotropic paramagnetic susceptibility in their LC phases. It is unclear whether the macroscopic magnetic structures of LC materials depend on the molecular orientational structures in the LC phases. Here, we report the persistence diagram of the macroscopic magnetic structures of an LC-NR on a ferromagnetic iron film in an image taken using photoemission electron microscopy. Furthermore, we discuss the topological aspect of the magnetic structures in the LC-NR by comparing the persistence diagram with that of the molecular orientational structures in a polarized optical micrograph of the same sample.

The single-source thermal vacuum evaporation (SSTVE) approach was adopted in this study to obtain inorganic perovskite thin films. The structural, morphological, compositional, and photoluminescent properties of the obtained layers were comprehensively investigated. X-ray diffraction analysis confirmed a microcrystalline structure with predominant CsPbBr3 and Cs4PbBr6 phases. Scanning electron microscopy images revealed a uniform polycrystalline morphology with crystallite sizes suitable for optoelectronic applications. Energy-dispersive X-ray spectroscopy indicated a Cs-rich composition, which was attributed to the differences in precursor vaporization behavior. The synthesized films exhibited strong photoluminescence with a distinct emission peak corresponding to the bandgap energy, confirming their potential as photoactive layers for light-emitting diodes. The SSTVE method provides a solvent-free, scalable route for fabricating high-quality inorganic perovskite films, suitable for industrial optoelectronic device manufacturing.

In the field of materials science, aluminum nitride (AlN) materials have great application potential in key fields, such as optoelectronic devices and high-frequency electronic devices, due to their unique optoelectronic properties. However, it is difficult to obtain the parameters related to its optoelectronic properties, and traditional measurement methods have low precision and poor efficiency. This study aims to solve this problem by constructing an attention-based deep neural network model to perform parameter inversion with high precision and efficiency. An experiment was conducted by employing a dataset comprising the optoelectronic properties of AlN materials, covering different preparation processes and crystal structure states, and the results were compared with an improved physical model (Model 1), a model based on statistical learning (Model 2), and a model based on traditional neural networks (Model 3). The results show that the deep learning model with attention has a significant advantage in terms of the measurement error rate, and the error rate of the light absorption coefficient is only 3.2%, which is much lower than that of Model 1 (12.5%), Model 2 (10.8%), and Model 3 (8.6%). In terms of the measurement efficiency, when the light absorption coefficient is measured as an example, the number of effective measurements per unit time can reach 50, which is far greater than that of the other models. This study provides a new way to measure the optoelectronic parameters of AlN materials and is expected to promote the development of related industries.

Hydrogen boride nanosheets (HB sheets), which are readily and reliably synthesized experimentally, have attracted attention as hydrogen storage materials. In this study, we performed density functional theory calculations of the HB sheets containing atomic vacancies to evaluate their hydrogen storage performance via hydrogen adsorption. Our results indicate that the adsorption of hydrogen molecules is enhanced by the introduction of a boron vacancy into the structure. Additionally, we re-evaluated the adsorption of a hydrogen molecule on the lithium-decorated HB sheet reported in a previous study, by employing a different set of computational parameters. Furthermore, by analyzing the electronic states, we discussed the underlying adsorption mechanisms. These findings indicate that structural modification alone could improve the hydrogen storage performance of the HB sheet.

Amorphous carbon (a-C) thin films are attractive materials for a wide range of applications. On the other hand, further modification of its surface can impart new features while retaining bulk characteristics. Surface modification of glassy carbon and graphite by electrochemical methods have been widely studied. However, there are relatively few reports on the surface modification of a-C thin films by electrochemical methods. The purpose of this study is to establish a method for the surface modification of a-C thin films with 4-aminobenzoic acid (4-ABA) by electrochemical oxidation and the characterization of the resulting 4-ABA-modified a-C thin films. The surface modification was performed by cyclic voltammetry (CV) in 10 mmol dm−3 phosphate buffer containing 4-ABA, using the a-C thin film deposited via pulsed laser deposition as a working electrode. The resulting surfaces have been studied by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy scratching. The XPS N 1s spectrum of the modified a-C surface revealed a peak at a binding energy of 399.5 eV which showed the formation of a carbon-nitrogen bond between the amino cation radical and carbon atom of the a-C thin film surface. The thickness of the modified layer formed by a single-cycle CV in a 1.0 mmol dm−3 solution of 4-ABA exceeded the molecular length of 4-ABA, indicating the formation of a multilayer of 4-ABA on the a-C surface.