Thin layers of indium tin oxide (ITO) were deposited onto glass substrates by RF magnetron sputtering with the pressure varying from 6 mTorr to 15 mTorr. The films were annealed in a reducing atmosphere at 500 °C for 30 minutes. Sheet resistance was determined by four-point-probe measurement. Resistivity, mobility, and carrier concentration were obtained by Hall effect measurements. Transmission of the films in the visible spectrum was determined by photospectrometry. The structure of the films was characterized by X-ray diffraction. X-ray photoelectron spectroscopy was used to determine the oxidation state of Sn, which was used to determine the fraction of active tin clusters. The effect of additional anneals was investigated. The results reveal that the lowest resistivity obtained was 1.69×10-4 -cm at 9 mTorr and the highest transmittance of 90% was obtained after a second anneal. However, the second anneal decreased the mobility and conductivity for high sputter pressures.

Aimed at designing an efficient visible light active photocatalyst and suppressing the self-corrosion tendency of CdS nanoparticles, a novel composite consisting of CdS nanoparticles and exfoliated two-dimensional (2D) TiO2 nanosheets was successfully fabricated using a simple self-assembly process. The prepared samples were characterized using various techniques including x-ray diffraction, ultraviolet–visible absorption spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. It was found that the exfoliated 2D nanosheets played an important role as an ultrathin coating to suppress the photocorrosion of CdS nanoparticles, evidenced by inductively coupled plasma-atomic emission spectrometer analysis. The resultant CdS/TiO2 composites exhibited enhanced photocatalytic activity in the oxidation of Rhodamine B in water under visible light irradiation (λ > 420 nm).

In this work were evaluated the microestructural characteristics by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) of the intermetallic γ'(liquation, coarsening and decomposition) in the Inconel 939 alloy after 40000 hours and 850–900°C aging operation conditions. The alloy was vacuum conventional cast. The results show that the liquation phenomena take place in eutectics γ-γ' which are present mainly in the core of the dendritic arms and in the coarse films of carbides along the grain boundaries (GB), the γ' particles change their original morphology of ordered cuboids of 320nm to disordered and coarse cuboids of 1.2μm, carbides show a morphology change from the original dispersed particles into a coarse continuous films and particles Chinese script type, this affects adversely the mechanical properties such as creep. The results of this evaluation allow to determine the main microestructural damage mechanisms which experiment some components such as blades at high temperatures in industrial conditions.

Trapping experiments have been performed at the Idaho National Laboratory to assess the performance of AgX sorbent media in capturing volatile iodine during the oxidation of irradiated oxide fuel. The demonstration of iodine release and capture from the used fuel has been accomplished with laboratory-scale equipment in a hot cell environment. Iodine loadings as high as 6 ug/g media have been achieved via chemical adsorption with filter efficiencies in excess of 90%. In addition to iodine, significant quantities of tritium have also been collected on the AgX filter media. Filter media loaded with radioactive iodine has been sequestered in a tin matrix by hot isostatic pressing at 200°C. The placement and encapsulation of the sorbent media was examined by neutron radiography, thus confirming the sequestration of radioactive iodine.

Lanthanum aluminate (Lax Al1−x Oy ; LAO) films doped with europium were deposited on a glass substrate by Ultrasonic Spray Pyrolysis technique. Like precursor solution was used 0.04M lanthanum nitrate and 0.04M aluminum nitrate in de-ionized water, and from europium nitrate was aggregated europium to 6%mol respect to LaO. The aluminum incorporated to rare earth oxides shows a high hydration resistance, therefore the films show stability in their luminescent properties. In this work the optical and morphological properties of the films are reported in the 350–600°C deposition range. The photoluminescent emission spectra show the characteristic peaks of the Eu3+ ion transitions: 5D0 → 7F0 (565 nm), 5D0→7F1 (596 nm), 5D0–7F2 at 615 nm and 623 nm, 5D0→7F3 (660 nm) and 5D0→7F4 (715 nm) for an excitation wavelength of 270 nm.

The adsorption of bovine serum albumin (BSA) and fibrinogen proteins dissolved on Phosphate buffer solution onto Ta, Nb and Ti oxide thin films was studied. The metal oxide thin films were deposited by magnetron sputtering on Si(100) wafers and characterized by contact angle measurements and profilometry. Spectroscopic ellipsometry was employed to characterize the kinetics of the protein adsorption process in-situ at the solid-liquid interface and the optical properties of the adsorbed protein layer formed after 45 minutes of immersion of the thin film in the protein solution. Infrared spectroscopy was used to study the proteins within the adsorbed layer. A trend indicating that the surface mass density of the adsorbed protein layer increases as the Rt (peak-to-valley height) surface roughness parameter increases was observed for fibrinogen and BSA. An increment in the surface mass density of the adsorbed protein layer was also observed onto surfaces with higher polar components of the surface energy. BSA and fibrinogen seemed to more readily adsorbed onto tantalum oxide than onto titanium oxide.

Thermodynamic considerations for the stability of Ni and Cr compounds developed under PWR environments (PH2O and PH2) are experimentally tested. In particular, the experimental outcome indicates that Ni(OH)2 and CrOOH are thermodynamically stable products under actual PWR conditions (T < 360°C and Pressures of up to 20 MPa). Accordingly, a mechanism is proposed to explain crack initiation and growth in inconel alloy 600 along the gbs. The mechanism is based on the existing thermodynamic potential for the transformation of a protective NiO surface layer into an amorphous non-protective Ni(OH)2 gel. This gel is also expected to form along the gbs by exposing the gb Ni-rich regions to H2 supersaturated water steam. Crack initiation is then favored by tensile stressing of the gb regions which can easily rupture the brittle gel film. Repeating the sequence of reactions as fresh Ni is exposed to the environment is expected to also account for crack growth in Inconel alloy 600. The proposed crack initiation mechanism is not expected to occur in alloy 690 where a protective Cr2O3 film covers the metal surface. Yet, if a pre-existing crack is present in alloy 690, crack propagation would occur in the same manner as in alloy 600.

Tungsten oxide nanorods (TONs) with the diameters of 40 nm and the length of 130 nm have been synthesized on substrates using two step electrochemical anodizing processes. The TONs were vertically well-ordered on the substrates with the average interdistance of 100 nm. The TONs had amorphous structure and was mainly composed of W, Al, and O elements, of which the contents varied gradually along the nanorod length from the top surface to the bottom. The cyclic voltammograms (CVs) and galvanostatic charge-discharge analyses showed that TONs had the typical electrochemical pseudocapacitive features of rectangular CV hysteresis and symmetric charge-discharge behaviors, respectively. When the TONs were heat-treated at 600℃ in vacuum, they showed the maximum specific capacitance of 660 ㎌/cm2, which was higher, by an order of magnitude, than that (68 ㎌/cm2) of the TONs annealed at 300 ℃ in ambient atmosphere.

Results of microbiological and geochemical sampling in the Outokumpu deep (2.5 km) borehole are presented. The results indicate that the discharging fractures control the observed variations in the microbial populations at different depths, which evidently reflect true variations in the microbial populations in fractures of the crystalline bedrock.

Composites of M-2.5 mol. % Fullerene C60 composites (where M= Fe or Al) are prepared by mechanical milling and Spark Plasma Sintering (SPS). The SPS technique has been used to consolidate the resulting powders and preserve the massive nanostructure. Results of X-Ray Diffraction and Raman Spectroscopy show that larger milling balls (9.6 mm in diameter) produce transformation of the fullerene phase during mechanical milling. Alternatively smaller milling balls (4.9 mm in diameter) allow retention of the fullerene phase. SEM shows homogeneous powders with different particle sizes depending on milling times. Sintering produces nanostructured composite materials with different reinforcing phases including C60 fullerenes, diamonds and metal carbides. The presence of each phase depends characteristically on the energy input during milling. Transmission Electron Microscopy (TEM) and Raman Spectroscopy show evidence of the spatial distribution and nature of phases. Diamonds and carbides can be identified for the sintered Fe containing composites with a relatively high volume fraction.

Large particles in fumed silica dispersions were characterized by sedimentation, light scattering techniques, Transmission Electron Microscopy (TEM), and lacunarity. Applying centrifugation to fumed silica dispersions generated differences in sedimentation rates of large particles. The sedimentation rates of the large particles were affected by morphological differences and the particles remaining in the supernatant displayed buoyant behavior. The large particle morphology varied from branch like aggregates containing large primary particles to particles comprised of highly coalesced, tightly packed small primary particles. The results indicate the presence of different types of large particles in fumed silica dispersions to which conventional large particle characterization is unable to distinguish.

A self-assembly driven process to synthesize island-structured dielectric films is presented. An intermetallic reaction in platinized silicon substrates provides preferential growth sites for the complex oxide dielectric (strontium-doped lead zirconate titanate) layer. Microscopy and spectroscopy analyses have been used to propose a mechanism for this structuring process. This provides a simple and scalable process to synthesize films with increased surface area for sensors, especially those materials with a complex chemistry.

Mesoporous molecular sieves MCM-41 modified by single (Ti) and bimetal (Ti-V) ions with highly ordered hexagonal arrangement of their cylindrical channels were prepared by direct synthesis under microwave–hydrothermal (M–H) conditions at 403K. Characterizations with powder X-ray diffraction (XRD), 29Si magic-angle spinning (MAS) NMR, N2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelcctron spectra(XPS) and transmission electron microscopy (TEM) showed that Ti and V ions were introduced into MCM-41 under M-H conditions and Ti/V-Si bond was formed. Results revealed that all the samples were of a typical hexagonal arrangement of mesoporous structure. The modified materials were high active and selective in the epoxidation of styrene at 343 K in comparison with single-functional MCM-41. Moreover, compared to conventional method, the presented microwave hydrothermal synthesis of molecular sieves greatly improved the selectivity to styrene oxide, e.g., it reached 58.6% at styrene conversion of 18.7% over Ti-V-MCM-41 (50).

Applications of nanocrystalline multiferroics in sensor development, massive memory storage or in the fabrication of new devices taking advantage of the electron charge and spin explains the need of investigating various options to synthesize these types of materials. Among promising candidates, Bismuth ferrite (BiFeO3) is a multiferroic material that exhibits ferromagnetism, ferroelectricity and ferroelasticity. The present research is focused on the systematic study of the polyol synthesis of substrate-less nanocrystalline BiFeO3 particles and its structural and magnetic characterization. As an attempt to explore the possibility of tuning the ferrite magnetic properties, host BiFeO3 was doped with cobalt ions in the 5at. % -10at. % range. Our results suggested that the ferrite formation and its properties were strongly dependent on both, the annealing conditions of the precursors and the concentration of cobalt species. Well-crystallized pure BiFeO3 was produced after annealing the precursor powders for one hour at 800oC. Doping with cobalt ions lowered the temperature at which the nanocrystalline BiFeO3 host structure was developed. The saturation magnetization and coercivity in the nanocrystalline ferrite were strongly influenced by the selected annealing temperatures and dopant concentration. These magnetic parameters varied from 0.30 emu/g and 109.5 Oe up to 4.2 emu/g and 988 Oe for pure and 10 at % Co-doped ferrite, respectively.

Actinide specific chelator (che) conjugated with magnetic nanoparticles (MNPs) have been developed to separate nuclear waste in acidic conditions. Compared to the traditional nuclear waste treatments, such as solvent extraction and ion exchange, this method is a simple, compact and cost-effective process that generates minimum secondary waste. In this paper, we focus on the coating process of MNPs to achieve a combination of good acidic resistance, high chelator loading density and efficient magnetic separation. An optimized silica coating process before conjugates chelator directly onto MNPs significantly improves the acidic resistance of the MNP-che complex. Chelator loading density is significantly increased by attaching a linear polyamine polymer poly(allylamine hydrochloride) (PAH) to the surface of the MNPs using chemical and physical approaches.

The very small number of known ferromagnetic superconductors places the study of such compounds at the frontier of superconductivity research. Recently, UCoGe has emerged as a new member of the class of materials exhibiting coexistence of ferromagnetism and superconductivity (Curie temperature TCurie = 3 K; superconducting critical temperature Ts = 0.8 K). This compound has generated much excitement, in part because it has been proposed that the superconductivity derives from spin triplet pairing mediated by ferromagnetic interactions. Therefore, a key question is how changes in the magnetic state of UCoGe affect the superconducting properties. We have carried out a comprehensive study of the UCo1-xFexGe and UCo1-xNixGe series of compounds across the entire range of composition 0 ≤ x ≤ 1. We report the results of x-ray diffraction, electrical resistivity, and magnetization measurements to elucidate the magnetic and superconducting phase diagram of the U[Fe, Co, Ni]Ge system. Substitution of either Ni or Fe into UCoGe initially results in an increase in the Curie temperature. At higher dopant concentrations (x), the ferromagnetic state crosses over to paramagnetism in UCo1-xFexGe and antiferromagnetism in UCo1-xNixGe.

The mechanism of haze reduction during silicon polishing using a new generation of additives has been explored. These additives are thought to decrease haze by adsorbing to the wafer surface and increasing the activation energy of the reaction between the silanolates on the silica particle surface with the surface silicon. This leads to greater selectivity between the peaks and valleys resulting in a net decrease in surface roughness.

Thermoelectric calcium cobalt oxide (Ca1.24Co1.62O3.86) with high Seebeck coefficient was prepared by self-propagating high temperature synthesis (SHS) followed by a short post treatment process. Synthesized samples were analyzed by XRD for their phase purity for samples prepared from different reactants mixtures. A final element model of SHS of calcium cobalt oxide was developed to study the temperature history and reaction rate change during the synthesis. This model can be used to predict reaction temperatures for various initial conditions.

The ultra-thin II-VI semiconductor ZnS/ZnO bilayers (< 50 nm thickness for each layer) can be easily formed on the plastic substrates at 70˜80°C for 20 min. By low temperature wet chemical synthesis techniques, namely chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR). The specific microstructure of such ZnS/ZnO bilayers including film thickness, particle size and morphology, is also modified and obtained in accordance with processing parameters. Along with thin film quality and morphology, the transmittance and reflectance of ZnS/ZnO layers can be measured by field emission SEM and UV-Vis spectroscopy. Besides the bilayer of ZnS (˜35 nm thick)/ZnO (˜50 nm thick) film with uniform thickness was successfully deposited on the optical grade PET substrates, a well-distributed layer of ZnO nanoparticles with ˜100 nm size on the top of ZnS (35 nm thick) film was also attempted. The average transmittance of these bilayer samples can reach greater 85%. Our future goal is to employ such ZnS/ZnO bilayer structure on potential organic substrates to be associated with flexible photovoltaic devices to meet desired cost-effectiveness requirements.

Photocatalytic destruction of the water soluble diesel fraction (WSF) was performed using Cu/TiO2 catalysts. Inexpensive and clean solar light and atmospheric oxygen were used as the energy source and oxidant, respectively. We investigated the effect of Cu species on the formation of a doping energy level between the conduction and valence band in TiO2. Photocatalytic reactions were investigated by monitoring the evolution of WSF as a function oftime of solar irradiation by UV-vis and FTIR spectroscopic techniques. The photocatalytic process in the presence of 5%Cu/TiO2 catalyst, is shown to be quantitatively efficient in the destruction of the water-soluble diesel fraction. The total destruction of water-soluble compounds originating from diesel residues indicates that photocatalysis can be employed for WSF treatment.