Mixed conduction in sodium vanadium bronze

The ionic and electronic conduction in α'-Na_xV₂O₅ prepared by the solid state reaction has been investigated. The electronic conductivity is nearly equal to the total conductivity and depends on the V⁴⁺ ion concentration. The Na⁺ ion conductivity was measured by a dc technique. The building up and decaying curves obtained at the transient polarization phenomena were analyzed by using a certain approximation for the steady state in order to save experimental time. The typical ionic conductivities were relatively low, namely 3×10^?6 and 2×10^?1 S cm?1 at 300°C for the samples of x=1.0 and 0.8, respectively which seemed to be dependent on the number of vacant Na⁺ ion sites.     

Triplet sensitized isomerization of a CCCN system. Energy surface of the triplet state and effects of azulene,oxygen, and di-tert-butyl nitroxide

The photostationary isomer ratios and quantum yields for triplet sensitized isomerization of the four isomers of a conjugated imine, l-methoxyimino-3-phenyl-2-propene, were determined to explore the reaction mechanism.     

Effects of some physical conditions on leaching rate of radon from radioactive minerals originating from some hot springs

In order to determine the best physical conditions for leaching more radon from minerals into water, we measured the leaching rate of radon from radioactive minerals under the conditions of some different grain sizes and water temperatures. Water temperature affected the leaching rate of radon although the grain size did not significantly affect it. Furthermore, we proposed ultrasonic irradiation to the mixture of a mineral and water as the method of leaching more radon. Ultrasonic irradiation was efficient to leach more radon from the mineral soaked in water because of ultrasonic cavitation.     

Concepts for chemical state analysis at constant probing depth by lab-based XPS/HAXPES combining soft and hard X-ray sources

The greater information depth provided in hard X-ray photoelectron spectroscopy (HAXPES) enables nondestructive analyses of the chemistry and electronic structure of buried interfaces. Moreover, for industrially relevant elements like Al, Si, and Ti, the combined access to the Al 1s, Si 1s, or Ti 1s photoelectron line and its associated Al KLL, Si KLL, or Ti KLL Auger transition, as required for local chemical state analysis on the basis of the Auger parameter, is only possible with hard X-rays. Until now, such photoemission studies were only possible at synchrotron facilities. Recently, however, the first commercial XPS/HAXPES systems, equipped with both soft and hard X-ray sources, have entered the market, providing unique opportunities for monitoring the local chemical state of all constituent ions in functional oxides at different probing depths, in a routine laboratory environment. Bulk-sensitive shallow core levels can be excited using either the hard or soft X-ray source, whereas more surface-sensitive deep core-level photoelectron lines and associated Auger transitions can be measured using the hard X-ray source. As demonstrated for thin Al₂O₃, SiO₂, and TiO₂ films, the local chemical state of the constituting ions in the oxide may even be probed at near-constant probing depth by careful selection of sets of photoelectron and Auger lines, as excited with the combined soft and hard X-ray sources. We highlight the potential of lab-based HAXPES for the research on functional oxides and also discuss relevant technical details regarding the calibration of the kinetic binding energy scale.     

Three-dimensional printing of conducting polymer microstructures into transparent polymer sheet: Relationship between process resolution and illumination conditions

Three-dimensional (3D) polypyrrole microstructures were successfully obtained in a transparent polymer sheet by 3D scanning of the laser focal point. The lateral process resolution of the microstructures was studied under different photofabrication conditions such as the repetition rate of the femtosecond pulse laser and the waiting time of the laser focal point scanning. As a result, a very small line width of the polypyrrole deposition of less than 500 nm was realized with good reproducibility.     

Both electron and hole Dirac cone states in Ba(FeAs)2 confirmed by magnetoresistance

Quantum transport of Dirac cone states in the iron pnictide Ba(FeAs)(2) with a d-multiband system is studied by using single crystal samples. Transverse magnetoresistance develops linearly against the magnetic field at low temperatures. The transport phenomena are interpreted in terms of the zeroth Landau level by applying the theory predicted by Abrikosov. The results of the semiclassical analyses of a two carrier system in a low magnetic field limit show that both the electron and hole reside as the high mobility states. Our results show that pairs of electron and hole Dirac cone states must be taken into account for an accurate interpretation in iron pnictides, which is in contrast with previous studies.