Tadaaki Nagao 교수

Our scanning tunneling microscopy and electron diffraction experiments revealed that a new two-dimensional allotrope of Bi forms on the Si(111)-7x7 surface. This pseudocubic [012]-oriented allotrope is stable up to four atomic layers at room temperature. Above this critical thickness, the entire volume of the film starts to transform into a bulk single-crystal (001) phase, as the bulk contribution in the cohesion becomes dominant. Based on ab initio calculations, we propose that the new allotrop

Matured surface chemistry and excellent chemical stability have enabled gold to become the material‐of‐choice for plasmonic sensing in both visible and infrared wavelength range. Here, successful surface functionalization of metamaterials made from a low‐cost abundant plasmonic material, aluminum, with phosphonic acid and subsequent detection of the CO vibration mode via surface‐enhanced infrared absorption spectroscopy is demonstrated. The metamaterial consists of infrared perfect absorbers fa

We have studied, for the first time, the energy and the linewidth dispersion of a plasmon in a dense two-dimensional electron system in a metallic surface-state band on a silicon surface. As expected from the considerably high effective density and long Fermi wavelength of the system, the plasmon energy dispersion exhibited an excellent agreement with the nearly free-electron theory. However, in a small wave number region below the Landau edge, we have observed an anomalous linewidth dispersion

Behaviors of domain walls on the Au-adsorbed $\mathrm{Si}(111)\ensuremath{-}\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ and $6\ifmmode\times\else\texttimes\fi{}6$ surfaces have been investigated by spot-profile-analyzing low-energy electron diffraction and scanning tunneling microscopy. A continuous change from the $\ensuremath{\alpha}\ensuremath{-}\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ pattern to the $\ensuremath{\beta}\ensuremath{-}\sqrt{3}\ifmmode\times\else\texttimes\fi{

We have measured one-dimensional (1D) plasmons in an atom wire array on the Si(557)-Au surface by inelastic scattering of a highly collimated slow electron beam. The angular dependence of the excitation energy clearly indicates the strong 1D confinement and free propagation of the plasma wave along the wire. The observed plasmon dispersion is explained very well by a quantum-mechanical scheme which takes into account dynamic exchange-correlation effects, interwire interactions, and spin-orbit sp

Plasmonic metamaterials are used for the fabrication of spectrally selective narrow-band mid-infrared thermal emitters operating at high temperatures. Using refractory materials, molybdenum and aluminum oxide in this case, high temperature operation has been demonstrated in vacuum up to 1000 °C. Colloidal mask etching is adopted to realize large-scale and cost-effective fabrication. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Suc

Our eyes and skin are routinely exposed to hazardous ultraviolet light (UV) from sunlight as well as to high-energy blue light (HEBL) from modern IT devices. Therefore, it is essential to protect our health by blocking this harmful high-energy radiation. In this study, we demonstrated a biodegradable, transparent, flexible film that blocks this dangerous radiation using cellulose-encapsulated, nitrogen-doped, carbon dots (NCDs). The interaction between cellulose and NCDs by H-bonding enables eff

Flat nano-island films prepared by wet-chemical deposition were investigated with attenuated total reflection infrared (ATR-IR) spectroscopy and scanning electron microscopy (SEM) in order to analyze the correlation between film morphology and optical properties. Here we choose Au as representative coinage metal (Au, Ag, Cu) that shows strong structure-dependent surface-enhanced infrared absorption (SEIRA). Infrared spectra of octadecanethiol monolayers on films of different stages of morphologi

Abstract An efficient method of water purification and desalination using anodized aluminum oxide (AAO) loaded with titanium nitride nanoparticles (TiN NPs) is demonstrated. While the ceramic TiN NPs convert the incident sunlight into thermal energy and generate a hot forefront region at the water–vapor interface, the AAO serves as an efficient transporter of water to this evaporating region through its nanochannels. It has been shown that photothermal performance of TiN–AAO can be optimized by

We report the fabrication of titanium nitride (TiN) films with the “best” plasmonic behavior reported so far by the pulsed laser deposition method. Even though the deposition is done at room temperature (∼25 °C) and grown on an amorphous native oxide of a silicon wafer, the plasmonic property of the TiN is comparable to that of gold, which is a conventional plasmonic material in the visible to near-infrared region. Because of the highly plasmonic nature of the TiN, the near field around the TiN