Search

A combinatorial rf magnetron sputter deposition technique was employed to investigate the electrical characteristics and microstructural properties of molybdenum tungsten (MoW) high temperature electrodes as a function of the binary composition. The effect of substrate bias and temperature was investigated.

A cylindrical electrode plasma process is developed to deposit diamondlike carbon (DLC) films on a polycarbonate-tube inner wall. The distribution of film thickness was observed to be 300-350nm and the structures of the DLC film were uniform.

Two-dimensional maps of the sheath electric fields formed around a metal-dielectric interface were measured in a radio frequency (rf) argon plasma using laser-induced fluorescence-dip spectroscopy. Dissimilar materials placed adjacent to each other result in electric fields with a component parallel to the electrode surface.

Sum frequency generation vibrational spectroscopy (SFG) and cyclic voltammetry (CV) measurements are conducted on the ionic liquid/platinum electrode system. The SFG spectra indicate that the cation changes orientation as the electrode potential is changed within the double-layer region.

The pattern of conductivity and electrochemical activity at the surfaces of hydrogen-terminated boron-doped diamond electrodes is calculated using conductive probe atomic force microscopy (CP-AFM) and scanning electrochemical microscopy (SECM). CP-AFM indicates that the surface is predominantly insulating, with discrete conducting areas of less than two macrometer in diameter and nonuniformly distributed on the surface.

An attempt is made to examine the effect pf flow field on the electric double layer distribution by means of a dilute electrolyte in a streaming potential mode for a 40 macrometer parallel-plate microchannel. By means of a current continuity equation, the numerical simulation results of potential distribution for pressure-driven flow with electrokinetic effects are presented.

The direct chemical synthesis of coloidal Co2+: TiO2 nanocrystals and the use of these nanocrystals for the preparation of thin films showing very strong room temperature ferromagnetism. It was concluded that very stron room temperature ferromagnetism can be obtained by processing nomogenous colloidal Co2+:TiO2 nanocrystals under aerobic conditions that preclude the formation of metallic cobalt.

The effects of different parameters on the utilization extent of a flow-through porous electrode operating the simultaneous reactions were investigated with the help of an effectiveness factor. The effects of ohmic resistance, mass transfer, kinetics, and bubble formation on the effectiveness factor for the main reaction were studied by using a mathematical model.

The problem of the formation of low-frequency arcs and well-defined semicircles in the impedance spectra of a variety of porous, composite Li intercalated electrodes, presented in the form of Nyquist plots are discussed. The appearance of the low-frequency semicircle with a high capacitance value, can be achieved by adopting a nonhomogenous, layered distribution of the active electrode mass.

A specific measurement technique and a calibration procedure are employed to estimate fast variations of the high-frequency impedance of ultramicroelectrodes (UME) under potential control. The technique allows real-time electrolyte-resistance Re measurements from an analogue signal, the amplitude of which is inversely proportional to the modulus of the UME impedance.

Thermodynamics of ion transfer across the liquid/liquid interface at a solid electrode shielded with a thin layer of water-immiscible organic solvent is studied. A commercial hydrophobic carbon filament material (LSG) as an electrode support, and a specially synthesized water-insoluble, redox, electroactive polymer (polyphenotiazine, PPTA) as a mediator, is used to make the hydrophobic-shielded electrode.

The anomalous IR properties of nanostructured films composed of Pt islands are investigated using CO adsorption as a probe reaction. Combination of in situ microscope Fourier transform infrared (FTIR) spectroscopy with an individually addressable array of Pt microelectrodes (ME(sub ij)) is used in combinatorial spectroelectrochemical analysis.

The relationship between the properties of ruthenium oxide and its electrode performance with respect to methanol electro-oxidation is investigated using a Pt-RuO2 nanocomposite thin-film electrode fabricated by a cosputtering system. The study concludes that improved electrical conduction that maintains the transport of protons is responsible for the enhanced electro-oxidation of methanol for 250 degree C Pt-RuO2.

ac conductance for the electrode effect in Li2B4O7 single crystal is investigated by use of a coplanar electrode applied on the surface of a (001) plate. The findings suggest that the electrode effect in ac conduction of Li2B4O7 single crystal is mainly due to the poor conductive surface layer distributed over the whole surface of the (001) plane and is not a secondary phase formed by reaction with the electrode material.`

Core and valence level photoemission spectra of Beta- and cubic-Si3N4 have been measured under monochromatic AlK(sub alpha) excitation. The measured valence band density of states for cubic-Si3N4 is in agreement with theoretical calculations.

The carrier mobility u in low-doped silicon-on-insulator wafers is found to be strongly modified by the deposition of a thin ZrO2 or SrZrO3 top layer grown by molecular-beam epitaxy. Using Hall-effect measurements, we took advantage of this additional current to evaluate the carrier mobility at the high-k/Si interface, without the need of a top gate electrode.

Fundamentally not requiring a vacuum chamber, atmospheric pressure glow discharges (APGDs) offer an exciting prospect for a wide range of material processing applications. Plasma dynamics, hence plasma stability, in these three modes are influenced crucially by impedance matching between the plasma rig and the power source.

The light harvesting efficiency of dye-sensitized photoelectrodes was enhanced, by coupling a TiO2 photonic crystal layer to a conventional film of TiO2 nanoparticles. The inverse opal photonic crystal caused a significant change in dye absorbance, which depended on the position of the stop band.

The preparation of integrated, electrically contacted, flavoenzyme and NAD(P)(super +)-dependent enzyme-electrodes has been described. The integration of the LDH with the two NAD(super +) cofactor configurations yields enzyme assemblies differing by 1 order of magnitude in their bioelectrocatalytic activities.

The electroreduction of O2 to water under physiological conditions at a currently density of 5 mA cm(super -2) and at a potential only 0.18 V reducing versus that of the reversible O2/H2O electrode at pH 7.4 is investigated. The potential application of this reaction carried out on immobilized electrode is suggested for use in flow systems and in bioinert films.

Solid-state molecular tunnel junction switching devices were fabricated by sandwiching LB monolayers of a bistable [2] catenane, a bistable [2] pseudorotaxane and a single station rotaxane between an n-type polysilicon bottom electrode and a titanium aluminum top electrode. All the devices showed a hysteretic current-voltage response that switched the device between high and low conductivity states although control devices exhibited no response. d

The electrical properties of nonirradiated and electron-irradiated thin layers of CdSe, sandwiched between two gold electrodes are investigated. The parameters characterizing the trap distribution and their changes induced by electron irradiation are obtained.

Temperature-programmed desorption method is used to analyze the working of prototype NO (sub x) sensors when Au/Pt electrode is present in automotive exhaust. Study of dissociation reaction of NO and O2 on Pt(335) and on partially Au covered Pt(335) report that the Au/Pt electrode in a NO (sub x) sensor is able to dissociate oxygen 10(super 3) times more efficiently than NO, which give indication for the development of new emission control systems.

A new approach to analyze the electrochemical impedance spectroscopy (EIS) data for electrodes covered by passivating surface films that grow in time is reported. The time-difference impedance spectra (DIS), which is the difference between two complex impedance curves, Z(omega, T1)-Z(omega, t2) measured after different period of storage, t1and t2 as a function of frequency provide an useful tool for characterizing the nature of the growing passivating films.

A new approach to analyze the electrochemical impedance spectroscopy (EIS) data for electrodes covered by passivating surface films that grow in time is reported. The time-difference impedance spectra (DIS), which is the difference between two complex impedance curves, Z(omega, T1)-Z(omega, t2) measured after different period of storage, t1and t2 as a function of frequency provide an useful tool for characterizing the nature of the growing passivating films.

The article presents a complete analysis of the various nanostructured work function electrodes that are formed from a metal layer and a base substrate. The application of these electrodes for different thermionic and thermotunnel devices is also discussed.

Time- and space-resolved light scattering experiments are performed in an industrial-type large area reactor with a variable interelectrode distance. The studies have shown that the onset of powder formation has depended on the product of the interelectrode distance and the gas residence time in the discharge.

Byline: P. Kyriazis, C. Anastasiadis, I. Stavrakas, D. Triantis, J. Stonham Experimental laboratory work was conducted to study the electric signals of marble beams that have been subjected to three-point bend tests. The specimens suffered 12 abrupt loading steps up to failure and the corresponding Bending Stimulated Current (BSC) was recorded by means of copper electrodes placed on the lower surface of the sample. Alongside the application of abrupt loading to the samples, BSC peaks were observed and the current followed an exponentially decreasing relaxation process. In this paper the BSC peaks, the total charge and the characteristic relaxation time variables are correlated with each other and are analysed towards the applied loading. The ultimate purpose of this work is the evaluation of the fatigue of the sample using simple criteria.

Byline: Bernard Nghiem, David Le Bellac The demand for a TCO coated glass substrate as a base material and front electrode of the solar cells is expected to grow very strongly in the next few years. Therefore it is crucial to prepare the industrial tools and proper glass compositions to meet this very impressive demand. Mass production of extra clear glass and atmospheric pressure thermal CVD tool installed directly on the float glass line are adapted processes to mass produce in a cost effective way fluorine doped tin oxide based TCO superstrates for PV application. From an industrial prospective, opto electrical trade off is an important issue. But maintaining the performances of the electrode during 20 years of function is a major concern too. In this paper, we will underline the durability issue of the SnO2 : F based electrode and specifically, electrochemical corrosion phenomenon due to electrical field assisted diffusion of alkaline ions from the glass toward the interface between the glass substrate and the TCO film. The DC electrical field responsible for this phenomenon is due to the difference of potentials between the grounded metallic frame of the PV modules and the TCO electrodes which are strongly negatively biased.

A liquid crystal (LC) display (LCD) mode is proposed and characterized by an azimuthally continuous nematic domain, driven by patterned electrodes with circular- and doughnut-shaped slits producing conelike fields as a vertically aligned (VA) nematic LC mode. The results have shown that the proposed LCD mode has shown high brightness and wide viewing angles and other electro-optics characteristics have corresponded to the patterned VA LC mode.