In the present paper, the authors investigated the microstructures and mechanical properties of dual-phase Co–Ti–V-based superalloys with different additions of Ru. The results showed that with the increase of Ru contents, the size of γ′ precipitates of the alloy gradually raised, the volume fraction of γ′ phase slightly, and the lattice misfit between γ/γ′ phases increased. Ru was enriched in the γ′ phase, and the elemental partition coefficients (KX = Cγ′/Cγ) of Ti and V increased with the increment of Ru. The Ru contents have no remarkable influence on the solvus temperatures of γ′ in the Co–Ti–V alloys. The yield strength at 1000 °C of the Co–10Ti–11V–0.5Ru alloy was the highest, while the yield strength of the 1Ru alloy was the smallest. Transmission electron microscopy and scanning electron microscopy observations showed that the γ′ shape in the compressed specimen containing 0.5Ru remain integrated, while the γ′ in other alloys were cut into several parts.

In this study I take men from Donghai, a region of northeast China, as a case study for examining models of success in the Western Han (206 b.c.e.–9 c.e.). Employing digital tools to mine data from The Grand Scribe's Records (Shi ji) and The History of the Western Han (Han shu), I explore the social networks and career patterns of men from a region that enjoyed a reputation for producing a remarkable number of high officials and celebrated Ru. I focus on three questions. First, what was the social mechanism that enabled people to distinguish themselves at both the local and the imperial levels? Second, did these celebrated men from Donghai serve as bridges connecting the local to the capital, directing resources back to their hometown and helping their local fellows achieve success? Third, did their positions in the central government remove them from local society by transforming them into capital-dwelling elites primarily concerned about the success of their families in the central court? In addressing these questions, I probe the dynamics between bureaucratic hierarchy, social networks, and the flow of talent and resources. I investigate various understandings of prestige and the strategies for climbing the ladder of success. Furthermore, I ask which forms of social prestige—for example, academic reputation, wealth, social networks—could bypass the hierarchical system imposed by the imperial bureaucracy, providing direct access to lofty positions. Did the patterns of success seen in the Donghai group reflect a bias built into the sources, constitute a regional variation, or provide a universal model for success in early imperial China?

Surface smoothing of Ru used as underlayer of magnetic tunneling junctions (MTJ) in magneto-resistive random access memory (MRAM) was carried out with gas cluster ion beam (GCIB) in order to improve device characteristics. For Ru films, surface smoothing with 5 kV N2-GCIB irradiation was effective, and CoFe films deposited on smoothed Ru surface also showed smooth surface. From the hysteresis loop measurements of MTJ formed on smoothed Ru with N2-GCIB, it showed improvement of inter-layer coupling magnetic field (Hin) with decreasing the surface roughness of underlayer Ru. It is expected that surface roughness of MgO in MTJ was also improved by smoothing of underlayer Ru with N2-GCIB.

Ruthenium-nitrosyl (RuII(NO)) complexes are stable in the dark, but exhibit a unique photoreactivity which can lead either to a solid state isomerization from RuII(NO) to RuII(ON), or to a nitric oxide (NO·) release in solution. From our recent discovery of a high yield of isomerization (> 92%) in [RuII(py)4Cl(NO)](PF6)2, we have developed a computational strategy aimed at designing switchable nonlinear optical (NLO) material with high contrast (large difference in the on / off NLO response) in the solid state. Our synthetic targets are terpyridine based RuII chromophores in which various substituents can be introduced to adjust the NLO response which, at best, should be vanishing in the off state. Alternatively, these complexes can undergo a photo-induced NO· release in solution, a possibility which becomes increasingly appealing in relation to the discovery of the numerous biological roles of NO·, in the context of the emergence of the photodynamic therapy. A promising fluorene-terpyridine RuII(NO) complex was investigated, which could find an additional interest in relation to its capability for releasing NO· by a two-photon absorption process.

Electrode catalysts composed of carbon supported PtRu nanoparticles (PtRu/C) synthesized by radiochemical process were annealed to control the PtRu substructure to enhance catalytic activity. The substructure of the PtRu nanoparticles synthesized by using high-energy electron beam under acidic condition was Pt-rich core/Ru-rich shell type, reflecting the redox potentials of each precursor ions. The material characterization techniques revealed that the reductive annealing led to the mixing of PtRu both in the core and on the surface. The sample with annealing temperature of 300°C for 5 hour showed the highest methanol oxidation current, 2.3 times higher than that obtained with before annealing.

In this paper we described using ruthenium (Ru) nanoparticles for surface modification on our hybrid PV/a-SiC photocathode for hydrogen production by water splitting under sunlight. Ru nanoparticles with size less than 5nm in diameter made the photocathode showed promising results: in an aqueous electrolyte an anodic shift of photocurrent onset potential around 450 mV and an increase in the photocurrent density up to 1.8mA/cm2 from a negligible value. Initial discussion the influence of Ru nanoparticles is presented.

In this study Ruthenium (II) tris (2, 2’-bipyridyl) complex in nonaqueous solution was studied by cyclic voltammetry and also its kinetic parameters were calculated. The redox reaction of ruthenium (II) trisbipyridyl complex is totally quasi-reversible and it can be described as a diffusion-controlled process. As a result of the redox reaction, the kinetic parameters of the electrode process such as diffusion coefficient (D), and heterogeneous rate constant (ks) were calculated. In addition, the different thermodynamic parameters such as standard free energy (ΔG#), enthalpy change (∆H#), and entropy change (∆S#) were determined and enthalpy change revealed the exothermic behavior of the electrode reaction. Both oxidation and reduction onset potentials of the ruthenium (II) trisbipyridyl complex was determined under the same experimental conditions to estimate the low ionization potential and electron affinity. The electrochemical and optical band gaps of the ruthenium (II) complex were compared.

Bi-functional oxygen electrodes are an enabling component for rechargeable metal-air batteries and regenerative fuel cells, both of which are regarded as the next-generation energy devices with zero emission. Nonetheless, at the present, no single metal oxide component can catalyze both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high performance which leads to large overpotential between ORR and OER. This work strives to address this limitation by studying the bi-functional electrocatalytic activity of the composite of a good ORR catalyst compound (e.g. palladium oxide, PdO) and a good OER catalyst compound (e.g. ruthenium oxide, RuO2) in alkaline solution (0.1M KOH) utilizing a thin-film rotating disk electrode technique. The studied compositions include PdO, RuO2, PdO/RuO2 (25wt.%/75wt.%), PdO/RuO2 (50wt.%/50wt.%) and PdO/RuO2 (75wt.%/25wt.%). The lowest overpotential (e.g. E (2 mA cm−2) - E (-2 mA cm−2)) of 0.82 V is obtained for PdO/RuO2 (25wt.%/75wt.%) (versus Ag|AgCl (3M NaCl) reference electrode).

Ruthenium dioxide (RuO2) was uniformly modified on TiO2 porous thin film by impregnation of Ru-contained dye on the film followed by sintering it at 450 °C to burn off organic matters and form ruthenium oxide, which is named as impregnation method. The homogenous modification of metal oxide inside porous thin film can be realized by the impregnation method, and the modification amount of RuO2 can be easily adjusted by the iteration numbers of impregnation and sintering. Appropriate amount of uniformly modified RuO2 was found to obviously enhance photocatalytic performance of TiO2 to degrade eosin Y. The photocatalysis enhancement was attributed to the shallow hole traps on the surface of nanoparticles formed by RuO2, and these traps can retard recombination of hole with electron.

Mo3Ru5MPd (M = Ru, Rh, Pd) as the simulated materials for the undissolved residue in the nuclear fuel reprocessing were prepared by arc melting method. The physical properties and oxidation behavior of the alloys were evaluated from viewpoint of the safety and economy in the reprocessing. The electrical resistivity, ρ, of Mo3Ru5RhPd was shown to be 0.8 μΩm at room temperature. On the other hand, the ρ values of samples without Rh were marked at 0.4 μΩm. The thermal properties of the each sample had the different thermal transfer characteristics. In particular, although the thermal conductivities of Mo3Ru5RhPd and Mo3Ru5Pd2 samples show almost the same value, the lattice thermal conductivities of both samples showed different values. Oxidation behavior was analyzed using the thermogravity(TG) and differential thermal analyses(DTA). The TG curve of each sample by oxidation showed different results. These results indicate that the simulated materials of the alloys without Rh: Mo-Ru-Pd were not appropriate to simulate the thermophysical characteristics of the typical simulated materials with undissolved residue Mo-Ru-Rh-Pd alloys. Therefore, in the spent nuclear fuel reprocessing, the mock test of reprocessing without to use Rh is difficult to carry out.

Nanoparticle catalyst of PtRuAu/C for direct methanol fuel cell anodes was synthesized by a radiolytic process. Its methanol oxidation activity and the electrochemical durability were evaluated by using the linear sweep voltammetry and the cyclic voltammety. The Au addition significantly improved the durability in comparison with PtRu/C catalyst without losing its high activity. The atomic structure was characterized with techniques of the transmission electron microscopy, the X-ray diffraction, the X-ray fluorescence spectroscopy and the X-ray absorption fine structure. These results implied that the arrangement of Pt and Ru atoms in the PtRuAu/C has no significant difference from that without Au, possessing a structure of Pt rich core and PtRu alloy shell. We concluded that the improvement in durability could originate from these PtRu nanoparticles decorated with Au, but not from particles with high Au contents.

In high level radioactive glasses, the low solubility platinoids (Pd, Ru, Rh) precipitate to form (Pd-Rh-Te, Ru-Rh, Ru) metallic particles and (RuO2, Rh2O3) oxides during the vitrification process. The composition and microstructures of these phases can significantly modify the physico-chemical properties and the electrical or thermal conductivities during melting.

Several studies are undertaken at CEA in order to point out the reactions and the chemical interactions in the liquid and viscous states between the glass matrix and the platinoids present in the calcinated waste. Among these studies, a thermodynamic fission products database is being developed on the metallic (Pd-Rh-Ru-Te) and oxide (O-Pd-Rh-Ru-Te) systems. In this work, based on the Calphad method, the Gibbs free energies of each phase are modelled to provide an overall thermodynamic description of the platinoid phases in nuclear waste glasses. The objective of the database is to facilitate calculations of phase diagrams and thermodynamic properties. This flexible tool also enables calculations of the relative stability between metallic and oxide phases in function of the oxygen potential (RedOx equilibrium).

For example, some solidification routes are calculated for typical Pd-Rh-Ru-Te compositions of LWR spent fuels. The calculated Pd-Rh-Ru-Te solidification paths are compared with the phases analysed in simplified laboratory scale glass samples. Using these results, the compositions of the Pd-Rh-Ru-Te inclusions are predicted. Furthermore, possible consideration of the RedOx equilibria for some ruthenium based phases makes it possible to explain the speciation between oxide and metallic phases partly due to the Pd-Te interaction.

By carefully manipulating and controlling the growth conditions, Ruthenium (Ru) and ruthenium oxide (RuO2) two-dimensional (2-D) nanostructure were self-assembled into a stack of plates on indium tin oxide coated glass substrate. The nanoplates were grown in a horizontal hot-wall metalorganic chemical vapor deposition (MOCVD) from ruthenocene. Each nanoplate has a thickness in the range of 25 - 60 nm and the average area is 1000 x 300 nm2. Each stack of nanoplates is approximately 1.2 m in height. A continuous layer of Ru and RuO2 thin film, which may serve as the growth template, is observed on the bottom of the nanoplate stacks. Field-emission scanning electron microscopy reveals that each stack of nanoplates was grown vertically aligned on the substrate and exhibited elongated shape. Structural properties which were examined by X-ray diffraction show that the nanoplates are polycrystalline.

The overarching goal of Dye Sensitized Solar Cells (DSSCs) is to improve photovoltaic performance and their long-term stability for use in practical applications because of their simple fabrication technology at a reasonable cost. The focus of this paper is to achieve cell stability and also to improve solar energy conversion efficiency experimenting with different electrolytes. The electrolyte’s role is critical to sustain the DSS cell performance over time to instill cell stability. Four different electrolytes, Iodolyte R-150, AN-50, PN-50 and MPN-100, are experimented in this work for fabricating the dye-sensitized solar cells for studying both the stability and efficiency of the DSSCs.

The electrolyte selection was made using the following key electrolyte parameters; lower viscosity for easier injection into the cell, lower vapor pressure and higher boiling point to minimize electrolyte evaporation, wide redox window to generate sufficient donating electrons to the dye, lower cost and non-toxicity. Electrolytes with higher concentration of Iodolyte were chosen for this study to widen redox potential window. These are Iodide based redox electrolytes and are made with 100 mM of tri-iodide in 3-methoxypropionitrile. The results of this investigation revealed that the cell with Iodolyte R-150 electrolyte achieved improved performance having an efficiency of 10.2% when compared to the reference cell efficiency of 8.4% with Iodolyte R-50. These cells were stabilized over a time of 4 weeks. The fill factor of the cell changed about 10% and the internal resistance decreased from 6.7 to 4.3 Ω. The results of this experiment demonstrated reduced internal resistance, and improved fill factor contributed to higher cell efficiency and stability. The results of the work presented in this paper support the argument that electrolytes with higher Iodolyte concentration can enhance the cell efficiency and stability along with scaling down of the cell size.

The Dye-sensitized Solar Cell (DSSC) has been regarded as the next-generation solar cell because of its simple and low cost fabrication process. The experiments for optimizing the cell efficiency were carried out in this work include varying the TiO2 layer thickness on the working electrode and determining the most favorable nanoparticle size in the TiO2 paste. The TiO2 electrode or working electrode was fabricated using screen printing technique with the Coatema tool with thicknesses ranging from ~20 to 66 μm. It was observed that both open circuit voltage and short circuit current were found to have measurable dependence on the TiO2 layer thickness. The open circuit voltage changed from 0.77 to 0.82 V and correspondingly the short circuit current also varied from ~19 to 23 mA/cm2 depending on the TiO2 layer thickness. Additionally, the cell with 40 μm TiO2 thickness showed 9.06% photo conversion efficiency compared to 6.4% and 8.5% efficiency obtained for the cells with 20 μm and 66 μm TiO2 thicknesses respectively. The second part of the experiment was conducted using three different nanoparticle sizes of 13 nm, 20 nm and 37nm in the TiO2 layer to identify optimum nanoparticle size by maintaining the TiO2 film thickness at 40 μm. The cell with 20 nm size nanoparticle, in combination with 40 μm TiO2 thickness showed 11.2% efficiency that is in par or slightly better than the efficiency value reported for the DSSC in the literature as of now. The work described in this paper showed best possible values for the TiO2 layer thickness and nanoparticle size in the TiO2 for obtaining improved cell efficiency of 11.2%.

Difficulties and challenges have been widely encountered in the chemical mechanical planarization (CMP) of noble metals used as diffusion barrier films due to hardness, chemical inertness and toxic oxidation products, in particular for Ru polishing. A commercial CMC Ru polishing slurry that successfully addressed the safety concerns was based on a high pH (8.4) polymer-treated-alumina-based multi-additive slurry containing complexing reagents (carboxylic acids and salts), corrosion inhibitors, surfactants, and hydrogen peroxide as a mild, non-aggressive oxidizer. Recently, our efforts had been redirected towards the development of a new generation of low pH barrier slurries based on an entirely new concept employing unique Lewis acid type abrasives. This class of materials is well known to be highly reactive in dielectrics polishing (ceria, zirconia, titania), but far less is known about their interactions with Ru, Cu or Ta.

In this presentation, we will elaborate the unexpected discovery that hard, chemically inert, noble metals such as ruthenium can be polished easily by virtually abrasive-free and/or oxidizer-free TiO2 based slurries. Of particular importance is the finding that the polymorphic phase of TiO2 (anatase or rutile), its surface chemistry (functional groups, Lewis acid/base character), pH induced surface modification and reactivity, can all mediate the abrasive particle's adsorption properties, catalytic activity and ultimately, its slurry polishing performance.

The effects of ruthenium (Ru)-oxidation states were investigated on Ru dissolution from PtRu thin-film electrodes, with the 200 cycles between 0.4 and 1.05 V (versus normal hydrogen electrode). The Ru-oxidation states of the PtRu thin films were systematically modified by an anodic (oxidation) treatment. The anodic-treated PtRu electrodes, whose methanol-oxidation activity was similar to untreated electrodes before the 200 cycles, showed a remarkable decrease in methanol oxidation after the cycles, because of the Ru dissolution from the PtRu surface. The results suggest that the Ru-oxide species are the origin of Ru dissolution in the PtRu alloy.

The effects of FePO4 nanoscale coating on PtRu thin films were investigated on the block of Ru crossover. Ru dissolution was examined by the accelerated-potential cycles between 0.4 and 1.05 V. The results showed that Ru dissolution from FePO4-coated PtRu surface was inevitable due to the direct contact between the PtRu surface and aqueous electrolyte. However, the FePO4 coating layer on PtRu thin-film electrodes effectively retained the dissolved Ru species, thus preventing the dissolved Ru species from diffusing into the electrolyte. Moreover, the retained Ru species within the FePO4-coating layer were redeposited onto the PtRu surface during the cycling in the fresh electrolyte.

Control of residual stress in thin films is critical in obtaining high mechanical quality coatings without cracking, buckling, or delamination. In this work, we present a simple and effective method of residual stress reduction in sputter deposited thin films by stacking low and high material density layers of the same material. This multilayer density modulated film is formed by successively changing working gas pressure between high and low values, which results in columnar nanostructured and dense continuous layers, respectively. In order to investigate the evolution of residual stress in density modulated thin films, we deposited ruthenium (Ru) films using a DC magnetron sputtering system at alternating argon (Ar) pressures of 20 and 2 mTorr. Wafer’s radius of curvature was measured to calculate the intrinsic thin film stress of multilayer Ru coatings as a function of total film thickness by changing the number of high density and low density layers. By engineering the film density, we were able to reduce film stress more than one order of magnitude compared to the conventional dense films produced at low working gas pressures. Due to their low stress and enhanced mechanical stability, we were able to grow these density modulated films to much higher thicknesses without suffering from buckling. Morphology and crystal structure of the thin films were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). A previously proposed model for stress reduction by means of relatively rough and compliant sublayers was used to explain the unusually low stress in the specimens investigated.