NiAl, YCu and TiAl polycrystals with B2 and L10 structure, respectively, have been deformed by high pressure torsion (HPT) at temperatures between 20°C and 500°C at a hydrostatic pressure of 8 GPa to high shear strains. Local texture measurements were done by diffraction of high-energy synchrotron radiation and X-ray microdiffraction. In addition, the microstructure was analyzed by electron backscatter diffraction (EBSD). Besides typical shear components an oblique cube component is observed with quite large rotations about the transverse direction. Based on the temperature dependence of this component as well as on microstructure investigations it is concluded that it is formed by discontinuous dynamic recrystallization. The influence of high pressure on recrystallization of intermetallics at low temperatures is discussed.

Blue and Green long-persistent luminescence materials have been fully developed, and are well featured in production and application. However, long-wavelength emitting materials are very rare relatively. This paper presents some work from our laboratory on the recent progress in long-wavelength emitting long-persistent luminescence materials: Sr3Al2O5Cl2: Eu2+, Tm3+, Sr2SnO4: Sm3+ and Ca2BO3Cl: Eu2+, Dy3+. The initial intensity of Sr3Al2O5Cl2: Eu2+, Tm3+ can reach nearly 5000 mcd/m2 and its afterglow can last about 220 min at recognizable intensity level. Sr2SnO4: Sm3+ has a red emission and its afterglow time of which sintered in vacuum atmosphere increased substantially. With optimum doping concentration and sufficient excitation with UV light, the yellow afterglow of Ca2BO3Cl: Eu2+, Dy3+ can persist over 48 h.

The combined focused ion beam/scanning electron microscopy/energy dispersive X-ray spectroscopy (FIB/SEM/EDX) system is a novel tool for the automotive catalysis field. Automotive emissions such as SOx, NOx, and particulate matter (PM) are regulated to various extents throughout the world, requiring the use of multiple aftertreatment components such as the diesel particulate filter (DPF), diesel oxidation catalyst (DOC), three-way catalytic converter (TWC), Lean NOx trap (LNT) and selective catalytic reduction (SCR). While these aforementioned aftertreatment components are generally multifunctional and robust in design, thermal and chemical aging over the components’ useful lifetimes results in significantly degraded performance leading to increased engine emissions levels and decreased fuel economy. While the component sizes themselves are generally large (10s of cm to ≈1/2 m), component aging mechanisms usually dominate on the nm-µm scales. In particular, this study has used the FIB/SEM/EDX system to investigate the aging of the diesel particulate filter (DPF) due to engine lubricant-derived inorganic ash accumulation. The FIB/SEM/EDX system has been used in the automotive aftertreatment field for the first time with many surprising and significant findings. Although the samples used in this study are quite different to those typically found in FIB studies, the authors have shown that the FIB/SEM/EDX system is a valuable tool in this research area, especially for the investigation of µm-size intra-particle structure and nm-µm interfacial/sub-surface details around the aged catalyst surface.

As the need for smaller data storage devices in the market continues to grow, the study of new combinations of self-assembled magnetic nanoparticles/films is greatly needed. In this research, Fe50-Ni50 films were synthesized using a Pulsed Laser Deposition technique. The films were analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and physical properties measurement system (PPMS). Films were deposited from Fe-Ni alloy target (50%-50% composition), deposition was conducted in vacuum, at substrate temperatures varying from liquid nitrogen temperature -196°C to 600°C. The films were annealed in a vacuum chamber at 600°C for 1 hour. The study reveals that the substrate temperature has significant effect on the structure of the films and their magnetic properties. It was shown that additional thermal treatment improved the quality of films in terms of narrow grain size distribution. Magnetic properties were also found to improve significantly after post annealing process.

Tin oxide is one of the popular metal oxide semiconductor used in solar cells, sensors, and catalysts. The surface modification by organic self assembled monolayer is one of the promising techniques to tune and to control the surface work function. In our study, we investigated the work function change of the SnO2 (110) surface which was modified with various benzoic acids derivatives using density functional theory (DFT). All calculations were carried out on Quantum Espresso program. Electron correlation and exchange parts were treated by local density (LDA), generalized gradient approximation (GGA) with Hubbard U term. To improve band structure calculation we used LDA+U method. The results of the calculation with LDA method indicated that the work functions of the pure and modified surface of SnO2 (110) with -C6H4-COOH molecule were calculated to be 7.40 eV and 6.18 eV, respectively. As the experimental value of work function of SnO2 (110) surface is about 7.74 eV, the results of the DFT calculation for pure SnO2 (110) surface modification by benzoic acid derivatives are in good agreement with the experimental.

We developed a simplified biofilm sorption and diffusion experiment method. The biofilms of the Bacillus cereus were incubated on cellulose acetate membrane filters (pore size 0.2 µm, diameter 47 mm) placed on thick NB broth agar medium (thickness was about 30 mm) to support sufficient biofilm growth of the Bacillus cereus. The thickness of the formed biofilms was about 1 mm. The formed biofilms were applied to through-diffusion method, which has been used to measure diffusion coefficient of crystalline and sedimentary rocks and clay minerals. The obtained copper sorption coefficient by batch experiments was about 100 ml/g (wet weight) at the case of the concentration of cupper ion was over 0.074mmol/L. And diffusion coefficients by through diffusion experiment was De=1.1 x 10-10 (m2/s). From these results, this simplified biofilm sorption and diffusion experiment may make possible to obtain these parameters with ease.

Raspberry-like composite spheres based on chemically-reactive poly(glycidyl methacrylate) (PGMA) colloids as the cores coated with tunable size of gold nanoparticles were synthesized via a controlled assembly method. Kinetic study of 4-nitrophenol reduction by NaBH4 in the presence of poly(allylamine hydrochloride)-modified PGMA composite with tunable size of AuNPs (PGMA@PAH@AuNPs) was demonstrated. Effects of gold nanoparticles size and PGMA colloid diameter on the reaction time, average reaction rate and average turnover frequency (TOF), order of reaction (n) and apparent rate constant (kapp) were systematically investigated. Experimental results of our study showed composites with 3.4 ± 0.9 nm AuNPs have the best catalytic efficiency with the highest reaction order and apparent rate constant. The poisoning of product 4-aminophenol on PAH-modified PGMA colloid-supported gold nanocatalysts was evaluated using 4-nitrophenol/NaBH4 reduction reaction for the reaction time, average reaction rate, average TOF, order of reaction and apparent rate constant.

A non-destructive neutron scattering method was developed to precisely measure the uptake of total hydrogen in nuclear grade Zircaloy-4 cladding. The hydriding apparatus consists of a closed stainless steel vessel that contains Zircaloy-4 specimens and hydrogen gas. By controlling the initial hydrogen gas pressure in the vessel and the temperature profile, target hydrogen concentrations from tens of ppm to a few thousands of ppm have been successfully achieved. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method (VHE), by which the samples with desired hydrogen concentration were selected for the neutron study. Small angle incoherent neutron scattering (SAINS) were performed in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). Our study indicates that a very small amount (≈ 20 ppm) hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes for a wide range of hydrogen concentration by a nondestructive method. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor, which is determined by calibration process with direct chemical analysis method on the specimen. This scale factor can be used for future test with unknown hydrogen concentration, thus provide a nondestructive method for absolute hydrogen concentration determination.

The Huastec region was conquered by the Aztec Empire during the reign of Moctezuma I (1440-1469), nevertheless no objects from this important place have been found for sure in the offerings of the Great Temple of Tenochtitlan until now. In this paper the Huastec affiliation of some Tenochca shell objects is discussed based on its comparison with pieces found in the Huastec region, from the stylistic and technological perspective. For the technological study of the objects experimental archaeology and SEM analyses are used.

We report here the fabrication and characterization of GaAs tunnel diode (TD) and ErAs nanoparticles (Nps) enhanced GaAs TD. Four GaAs TDs with different contact area were fabricated by using MOCVD. We found extremely high peak current density of ∼250A/cm2 for the TD with r=0.25mm contact area. Moreover a hysteresis loop was appeared during sweeping up and sweeping down the external voltage. A ‘vector load line model’ was proposed to explain the origin of the shape of the hysteresis loop and the onset of the bistability occurred at the intersect of the loadline and the current-voltage (I-V) curve of TD. Meanwhile, we have grown ErAs Nps on GaAs(100) surface by using MBE and succeeded in overgrowth of GaAs after ErAs deposition. GaAs(p+)/ErAs(Nps)/GaAs(n+) TDs were fabricated and characterized. We found the GaAs sample containing 70s deposition of ErAs showed the best TD behavior. No TD behavior was observed for the sample without addition of ErAs Nps, clearly indicating the strong tunneling enhancement effect from ErAs Nps.

Nb-doped TiO2 (TNO) films, Ga-doped ZnO (GZO) films and TNO/GZO layered films were fabricated on glass substrates and electrical properties of TNO/GZO layered films were investigated in terms of interaction between TNO and GZO layers. By a thermal annealing in vacuum, the observed resistivity of the TNO/GZO layered films was lower than that of the single layered films fabricated and annealed at the same conditions. The resistivity reduction observed in the layered structure is not explained by the parallel connection of the TNO and GZO layers, indicating that there exists an interaction between these two layers. The TNO/GZO films with low resistivity have still been transparent.

The forward voltage degradation in 4H-SiC PiN diodes with a simplified process and that in 4H-SiC pin diodes with additional processes are investigated. Photoluminescence images were also observed to identify the cause of forward voltage degradation. The forward voltage degradations of 4H-SiC PiN diodes with additional processes were larger than those with a simplified process. Observing photoluminescence images of diodes after a current stress test showed that less than 25% of Shockley-type stacking faults in 4H-SiC PiN diodes with a simplified process are caused by half-loop dislocations, which are generated not only in the additional processes but also in the whole device fabrication process. With additional processes, those rates are over 65%, which may be reduced by eliminating half-loop dislocations due to the optimization of the process condition and sequence.

The paper argues that solar photovoltaic or wind systems would need to be implemented at a rate of hundreds of gigawatts each year to obviate the continuing worldwide growth of fossil-fueled electricity generation. It suggests that an electricity consumption tax could constitute a sustainable mechanism for funding such an endeavor.

It is observed that the atmospheric content of carbon dioxide rose by approximately 16 Gt in 2012. A non-negligible contribution to this increase must surely have come from the 35 Gt of CO2 emitted by fossil fuel consumption that year, of which 11 Gt came from fossil-fueled electricity generation (FFEG). Yet, new FFEG plants continue to be built. Although it is questionable whether economic forces would permit a halt to the construction of such plants, it is argued that, from the perspectives of technology, manufacturing capability, land availability, and cost, it could be feasible to use solar photovoltaic and wind plants to provide for the annual increase in the worldwide need for electricity. However, the required capital expenditure cost of approximately US$ 0.5 trillion per year might be difficult to raise by conventional methods for funding renewable energy plants. A number of alternative funding mechanisms are examined. Among them, an electricity consumption tax is found to be capable of providing an assured amount of regular funding on this scale. In North America and Europe, such a tax would add approximately 1 US¢/kWh to present electricity tariffs. In other regions, it would amount to an addition of 2–5 US¢/kWh.

Diamond is a unique material in many respects. One of the most well-known extreme properties of diamond is its ultrahardness. This property of diamond actually turns out to have interesting consequences for charge transport, in particular at low temperatures. In fact, the strong covalent bonds that give rise to the ultrahardness results in a lack of short wavelength lattice vibrations which has a strong impact on both electron and hole scattering. In some sense diamond behaves more like a vacuum than other semiconductor materials. In this paper we describe some interesting charge transport properties of diamond and discuss possible novel electronic applications.

A nano thermal sensor was made by depositing carbon nanotubes from a medium containing a) methylene chloride b)sodium dodecyl sulfate and c) Baytron-P (polymer) assisted sodium dodecyl sulfate. The nano thermal sensors showed d.c. electrical resistance as independent of temperature when the sensors were made by procedures (a) or (b). The electrical resistivity in both the situations has been independent of temperature. When the nanosensor is made with carbon nanotubes by assisted method (c), the d.c. electrical resistance decreased with temperature. The negative temperature coefficient (TCR) is manifested in the semiconducting property of the active material. The sensor behavior is reproducible and varies linearly with temperature. The nanosensor made by non assisted carbon nanotube showed zero TCR. This is probably the first instance of assisted thermal sensor made with single walled carbon nanotubes.

Cu2ZnSnSe4 (CZTSe) precursor films were deposited by one-step RF sputtering process at room temperature under various sputtering power, and then films were annealed at different pressure of 10-3 Pa and 100 Pa. Films annealed at high vacuum of 10-3 Pa exhibit significant loss of Sn element and they construct with two phases of Cu1.8Se and ZnSe. Higher annealing pressure at 100 Pa can drastically reduce the loss of Sn element and result in single kesterite CZTSe phase of the annealed films. Loss of Se element is found in all the annealed films and the values of [Se]/[Metal] and [Sn]/[Zn] are related with sputtering power. High vacuum annealed films show cracks and porous structure on the surface, meanwhile, films annealed at 100 Pa show compact, densely packed homogeneous morphology.

Stoichiometric 4H-SrMnO3.0 nanoparticles have been successfully synthesized for the first time from thermal decomposition of a new heterometallic precursor [SrMn(edta)(H2O)5]·3/2H2O. From this precursor, highly homogeneous 4H-SrMnO3.0 nanoparticles with average particle size 70 nm are obtained. Local structural information, provided by atomically-resolved microscopy techniques, shows that 4H-SrMnO3.0 nanoparticles exhibit the same general structural features than the bulk material, although structural disorder, due to edge-dislocations, is observed. The nanometric size of particles enables a topotactic reduction process at low temperature stabilizing a metastable 4H-SrMnO2.82 phase. The oxygen deficiency is accommodated through extra cubic layers breaking the …hchc… 4H-sequence. These defect areas are Mn3+ rich as evidenced by high energy resolution EELS data. Magnetic characterization of nano-4H-SrMnO3-δ shows significant variations with respect to the bulk material.

The combination of density functional theory in local density approximation and dynamical mean field theory (LDA+DMFT) was employed in a preliminary study of the strong electron correlation effects in a promising nuclear fuel—uranium mononitride (UN). For the ferromagnetic phase, the effective impurity problem arising in the LDA+DMFT [1-3] cycle is solved with the spin-polarized T-matrix fluctuation exchange (SPTF) solver, which includes spin–orbit interactions. Concerning the paramagnetic phase, the disordered local moment (DLM) approach was used, based on both standard local density approximation (LDA) and LDA+U. Basic spectral properties and material properties, such as the spin, orbital and total magnetic moments on U atom were calculated for various values of the Hubbard parameter U with a fixed exchange parameter J. Our main focus was to compare the calculated spectral functions (density of states) for different magnetic phases and different methods to the experimental XPS data [4]. On top of that, the total moments of the paramagnetic and ferromagnetic phases are compared with the measured values by neutron spectroscopy [4, 5].

The formation of triplet excitons in semiconducting organic materials plays an important role for the operation of organic optoelectronic devices. Triplet excitons are difficult to investigate spectroscopically at room temperature due to their non-radiative character. Here we show the measurement of the triplet decay dynamics by a highly sensitive time-resolved measurement of the triplet state absorption using pump and probe experiments within a waveguide configuration. Pump and probe pulse have to be separated spatially and in time to ensure a segregation of singlet and triplet excitons. The non-radiative triplet excitons are detected at room temperature by their absorption. A variation of the time delay between pump and probe pulse allows for the investigation of the dynamics of the excitons. Former experiments made use of the photoluminescence of the material under investigation itself as source of probe light. But since there is a spectral shift between the photoluminescence band and the triplet absorption band the spectral bandwidth of probe light has to be broadened for the identification of the triplet absorption. Here we show how a widening of the probe light band up to red part of the spectrum is achieved by an application of extra emission layers. With the help of this technique the triplet exciton dynamics of the hole transport material 2,2',7,7'-tetrakis(diphenylamino)-9,9'-spirobifluorene (SpiroTAD) was measured and analyzed.