Fuminori Misaizu

Bio: Fuminori Misaizu is an academic researcher from Tohoku University. The author has contributed to research in topics: Ion & Dissociation (chemistry). The author has an hindex of 23, co-authored 117 publications receiving 2144 citations. Previous affiliations of Fuminori Misaizu include Tokyo Institute of Technology & Graduate University for Advanced Studies.

Photodissociation study on Mg+(H2O)n, n=1–5: Electronic structure and photoinduced intracluster reaction

Abstract: Photodissociation spectra of Mg+(H2O)n (n=1–5) cluster ions were examined in the wavelength region from 720 to 250 nm by monitoring the total yield of the fragment ions. The absorption bands exhibit redshifts as large as 17 000 cm−1 with respect to the 2P–2S resonance line of the free Mg+ ion and were explained by the shift of this transition as a result of hydration. The spectra also exhibit clear evolution of solvation shell with the first shell closing at n=3, being consistent with the theoretical prediction. The mass spectra of the fragment ions show the existence of two dissociation processes: the evaporation of water molecules and the photoinduced intracluster reaction to produce the hydrated MgOH+ ion, MgOH+(H2O)m. The branching fraction between the two processes depends strongly on the solvent number n and also on the photolysis wavelength. The energetics and the dynamics of the dissociation processes were discussed in conjunction with the results of ab initio calculations.

Near threshold photoionization of silicon clusters in the 248–146 nm region: Ionization potentials for Sin

Abstract: Photoionization thresholds for silicon clusters in the size range Si2 to Si200 have been examined by laser photoionization with detection by reflectron time‐of‐flight mass spectrometry. Stimulated Raman scattering light of narrow bandwidth 193 nm radiation was used as the ionization light source down to 146 nm. A characteristic size dependence of ionization potentials (IPs) was found for clusters smaller than 22 atoms, featuring major maxima at n=10 and 20. We also found a large gap in IPs between n=20 and 22. This gap was ascribed to the structural transition of neutral clusters in analogy with that found recently for small silicon cluster ions. The IPs for larger clusters with n=100–200 silicon atoms were found to be 5.0–5.17 eV, which are lower than the ionization energy but still higher than the work function of bulk Si(111) surface. This difference was discussed with relation to the nature of surface states for both phases.

Photodissociation of size-selected Mg+(H2O)n ions for n = 1 and 2

Abstract: Electronically excited states or magnesium-water cluster ions, Mg + (H 2 O) n , are studied by photodissociation after mass selection Dissociation spectra are obtained as a function or wavelength for n=1(250-370 nm) and 2 (280-470 nm) The spectra show absorption peaks at 28300, 30500, and 38500 cm -1 for n=1, and 25000, 29400, and 32000 cm -2 for n=2

Structural properties of nanoclusters: Energetic, thermodynamic, and kinetic effects

Abstract: The structural properties of free nanoclusters are reviewed. Special attention is paid to the interplay of energetic, thermodynamic, and kinetic factors in the explanation of cluster structures that are actually observed in experiments. The review starts with a brief summary of the experimental methods for the production of free nanoclusters and then considers theoretical and simulation issues, always discussed in close connection with the experimental results. The energetic properties are treated first, along with methods for modeling elementary constituent interactions and for global optimization on the cluster potential-energy surface. After that, a section on cluster thermodynamics follows. The discussion includes the analysis of solid-solid structural transitions and of melting, with its size dependence. The last section is devoted to the growth kinetics of free nanoclusters and treats the growth of isolated clusters and their coalescence. Several specific systems are analyzed.

Broad family of carbon nanoallotropes: classification, chemistry, and applications of fullerenes, carbon dots, nanotubes, graphene, nanodiamonds, and combined superstructures.

Abstract: and Applications of Fullerenes, Carbon Dots, Nanotubes, Graphene, Nanodiamonds, and Combined Superstructures Vasilios Georgakilas,† Jason A. Perman,‡ Jiri Tucek,‡ and Radek Zboril*,‡ †Material Science Department, University of Patras, 26504 Rio Patras, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 listopadu 1192/12, 771 46 Olomouc, Czech Republic

Colloquium: The quest for high-conductance DNA

Abstract: The DNA molecule, well known from biology for containing the genetic code of all living species, has recently caught the attention of chemists and physicists. A major reason for this interest is DNA's potential use in nanoelectronic devices, both as a template for assembling nanocircuits and as an element of such circuits. Without question, a truly conducting form of DNA would have a major impact on developments in nanotechnology. It has also been suggested that extended electronic states of DNA could play an important role in biology, e.g., through the processes of DNA damage sensing or repair or through long-range charge transfer. However, the electronic properties of DNA remain very controversial. Charge-transfer reactions and conductivity measurements show a large variety of possible electronic behavior, ranging from Anderson and band-gap insulators to effective molecular wires and induced superconductors. Indeed, understanding the conductance of a complicated polyelectrolytic aperiodic system is by itself a major scientific problem. In this Colloquium, the authors summarize the wide-ranging experimental and theoretical results and look for any consistencies between them. They also pose simple questions regarding the electronic states of DNA within the framework of generalized H\"uckel and Slater-Koster theories. The Colloquium provides a quantitative overview of DNA's electronic states as obtained from density-functional theory, focusing on dependence on structure, on molecular stretching and twisting, and on water and counterions. While there is no clear theoretical basis for truly metallic DNA, situations are discussed in which very small energy gaps might arise in the overall DNA/water/counterion complex, leading to thermally activated conduction at room temperature.

Clusters: Structure, Energetics, and Dynamics of Intermediate States of Matter

Abstract: The field of cluster research can trace its origins back to the mid-nineteenth century when early studies of colloids, aerosols, and nucleation phenomena were reported. The field underwent a resurgence of interest several decades ago when well-defined clusters were observed in supersonic expansions that could be investigated using mass spectrometers. The advent of the laser provided a new dimension, enabling detailed spectroscopic observations through the probing of systems of varying size and degree of solvation. Modern interest derives from recognition that interrogating clusters provides a way of studying the energetics and dynamics of intermediate states of matter as cluster systems evolve from the gas toward the condensed state. Herein, we endeavor to highlight some of the significant advances which have been made during the past several decades that have led to a nearly explosive growth of interest in the field of cluster science. Finally, we conclude that the field will continue to expand through i...

Review of Recent Developments in the Field of Magnesium Corrosion

Abstract: This paper provides a review of recent developments in the field of Mg corrosion and puts those into context. This includes considerations of corrosion manifestations, material influences, surface treatment, anodization, coatings, inhibition, biodegradable medical applications, stress corrosion cracking, flammability, corrosion mechanisms for HP Mg, critical evaluation of corrosion mechanisms, and concluding remarks. There has been much research recently, and much research continues in this area. This is expected to produce significantly better, more-corrosion-resistant Mg alloys.