Understanding spatial heterogeneity in catalytic activity is essential for designing efficient hydrogen evolution reaction (HER) catalysts. In this study, scanning electrochemical cell microscopy (SECCM) was employed to directly image local HER activity on transition metal dichalcogenide (TMD) nanosheets. By resolving nanoscale electrochemical responses beyond conventional electrochemical measurements, SECCM revealed heterogeneous activity distributions associated with edges, morphology, and strain. Local analyses of nanoribbons, dendritic structures, and strain-engineered layers clarified how geometric and electronic modifications influence catalytic performance. These findings establish direct structure–activity correlations at the nanoscale and demonstrate the capability of SECCM as a powerful platform for guiding the design of next-generation non-precious HER electrocatalysts.

Ag stripe formation on the Ni(110) surface was studied using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED) and first-principles calculations. Ag forms self-limited one-dimensional stripes with fluctuating edges. The stripes consist of one-dimensional Ag clusters in the [110] direction, stabilized by lattice-mismatch-induced confinement, dynamic edge instability near a critical size, and one-dimensional Ag 5s band formation. These results highlight a cooperative structural and electronic mechanism in the formation of Ag stripes on the Ni(110) surface.

We report a molecular-scale study of a one-dimensional coordination polymer formed on a Cu(111) surface. A tailored ligand, 2,7-dicyano-9,9-dimethylfluorene (DCF), was designed to reduce interactions with the surface while enabling directional coordination with Cu adatoms. Scanning tunneling microscopy reveals that the resulting DCF–Cu polymer exhibits pronounced flexibility dominated by the CN–Cu–CN coordination angle, which constitutes the primary internal degree of freedom governing the overall chain geometry. Temperature-dependent measurements show the onset of thermal motion above ～40 K for linear chain segments, whereas three-coordinated branches remain immobile up to 71 K, functioning as molecular-scale cross-links. These results directly connect polymer physics concepts with single-molecule motions on surfaces.

Layered two-dimensional (2D) van der Waals magnetic crystals based on 3d transition metals and chalcogenides are typically synthesized by chemical vapor transport, while establishing epitaxial, layer-by-layer growth under vacuum remains essential for device applications. Here, we study Mn–Te as a model system motivated by its intriguing topological and magnetic properties. Our findings using scanning tunneling microscopy and spectroscopy (STM/STS) combined with density functional theory calculations reveal that film growth initially results in a mixture of Te-, Mn-, and MnTe-related metastable phases. Upon post-annealing up to ～650 K, these states transform into a thermodynamically stable MnTe alloy phase, yielding an atomically flat 2D surface. This work further demonstrates that integrating machine learning with STM/STS enables reliable chemical classification and identification of local density of states in structurally complex surfaces.

Electric-field control in multiferroic materials is attracting attention for next-generation memory devices with low power consumption and non-volatility. This review overviews magnetization reversal in cobalt-substituted BiFeO₃ (BiFe_1－xCo_xO₃), a single-phase room-temperature multiferroic material. Experimental results from microscopic direct observations of domain structures using scanning probe microscopy are summarized, highlighting how electric-field-induced magnetization-reversal is influenced by domain structures, film orientations, and switching angles. These insights offer a clear perspective toward magnetoelectric memory applications of BiFe_1－xCo_xO₃.

This article reflects on the author's research career and thoughts, emphasizing the importance of crossing disciplinary boundaries to cultivate originality as a scientist. Drawing on experiences in surface and interface science, thin films, electrochemistry, solid-state ionics, and industry (marketing and product planning), the author argues that innovation emerges from integrating diverse disciplines and systemizing knowledge. The article highlights lessons learned from own failures. Ultimately, the author encourages researchers to embrace challenges, enjoy exploration, and build original identities through interdisciplinary research.

A numerical analysis has been obtained on the distribution of the molecular flux density q_o(r) at the pump aperture of a test dome for measuring the speed of a high vacuum pump. The caluculation was carried out based on solving Clausing's integral equation by using iterative approximation method. It is found that q_o(r) slightly decreases with increasesing radius, which might not affect the accuracy of measurement of the speed of the pump. For further consideration of the basic aspect of this phenomenon, numerical analysis was also carried out for cylindrical tube. Similar tendency was resulted on the molecular flux density distribution at the exit of the cylinder.

Atomic layer deposition (ALD) methods are attracting attention because these can achieve surface reactions by chemically reacting only with raw material molecules adsorbed to solid surfaces. Two highly chemically reactive raw material gases are injected alternately, and a vacuum is drawn between them to suppress spatial reactions. Because the films are fabricated by repeated adsorption and reaction of the raw materials, the film deposition rates are extremely slow. However, because the manufacture of modern functional devices requires the deposition of nanometer-level films on highly uneven substrates, the slow film deposition rates are no longer seen as a drawback, but rather as an advantage in terms of film thickness control.

While ALD methods have been put into practical use as a new technology, these are still in the process of establishing surface technologies through the application of vacuum science, and these are methods those are currently undergoing rapid researches and technological developments.