Showing papers on "Silver oxide published in 2010"

Spectroscopic Evidence for Ag(III) in Highly Oxidized Silver Films by X-ray Photoelectron Spectroscopy

Abstract: In situ X-ray photoelectron spectroscopy (XPS) was utilized to identify the chemical state of silver in a range of silver oxide thin films obtained by codeposition of silver and atomic oxygen. A highly oxidized silver species was observed at an unexpectedly low Ag 3d5/2 binding energy (BE) of 366.8 eV with an associated broad satellite at 368.2 eV; this species was assigned as Ag(III). It was found to be highly unstable in vacuum but could be regenerated by further exposure to atomic oxygen. Both BE shifts and intensity changes of the O 1s peak were found to correlate with changes in the silver oxidation state. The theoretical XPS spectrum of high spin Ag(III) was calculated for both an isolated cation and an embedded AgO6 cluster.

The aluminium and iodine pentoxide reaction for the destruction of spore forming bacteria

Abstract: The threat of biological weapons is a major concern in the present day and has led to studying methods to neutralize spore forming bacteria. A new technique involves the use of a thermite reaction that exhibits biocidal properties to limit bacterial growth. The objective was to examine the influence on bacteria growth upon spore exposure to thermite reactions with and without biocidal properties. Three thermites are considered: two that have biocidal properties (aluminium (Al) combined with iodine pentoxide (I(2)O(5)) and Al combined with silver oxide (Ag(2)O)); and, one that produces a highly exothermic reaction but has no biocidal properties (Al combined with iron oxide (Fe(2)O(3))). Results show that Al + I(2)O(5) is extremely effective at neutralizing spores after only one hour of exposure. The temperature generated by the reaction was not determined to be an influential factor affecting spore growth kinetics. Further analysis of the thermite reactions revealed that the Al + I(2)O(5) reaction produces iodine gas that effectively interacts with the spores and neutralizes bacteria growth, while the Al + Ag(2)O reaction temperature does not vaporize silver. In the condensed phase silver does not interact with the spores enough to neutralize bacteria growth. This study gives evidence that a thermite can be used as a stable transportation and delivery system for biocidal gas.

Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

Abstract: The electrical conductivity of a silver microflake-filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF-SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF-SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four-point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the −40 ∼ 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component.

Influence of UV irradiation and ozone on atmospheric corrosion of bare silver

Abstract: The corrosion of Ag in an atmosphere of ozone and humidity with or without irradiation by ultraviolet (UV) light was investigated. A modified coulometric reduction technique was used, substituting sulphate solution for chloride solution, to prevent the spontaneous transformation of silver oxide corrosion product to chloride in the reduction solution. The presence of both ozone and UV radiation was required for fast corrosion of Ag to occur. The amount of corrosion product for a given exposure time increased with ozone concentration, whereas the relative humidity had little effect. An incubation time for the corrosion reaction was observed. The presence of both ozone and UV radiation were necessary for rapid corrosion because the photodissociation of ozone generates reactive atomic oxygen, which reacts with Ag rapidly to form Ag2O. The corrosion reaction on bare silver was minimally affected by the relative humidity in the environment, which is contrary to common atmospheric corrosion experience.

Electrically conductive bonding material, method of bonding with the same, and semiconductor device bonded with the same

Abstract: The present invention provides a bonding material and a method of bonding for metal bonding at a bonding interface capable of a higher bonding strength at a lower temperature without application of pressure, compared to a bonding material of metal particles having an average particle size of not greater than 100 nm. An electrically conductive bonding material including (A) silver particles, (B) silver oxide, and (C) a dispersant including organic material containing not more than 30 carbon atoms as essential components, wherein a total amount of (A) the silver powder, (B) the silver oxide powder, and (C) the dispersant including an organic material containing not more than 30 carbon atoms is in a range of 99.0% to 100% by weight, is provided. In other words, no resin binder is contained.

Silver Schottky contacts to a-plane bulk ZnO

Abstract: The temperature dependent electrical properties of Ag Schottky contacts to a-plane bulk ZnO single crystal were investigated in the temperature range of 100–300 K. The variation in the barrier heights was described by a double Gaussian distribution with two different regions in the temperature range of 200–300 and 100–180 K. The modified Richardson plot in the temperature range of 200–300 K produced the Richardson constant of 29 A cm−2 K−2 which is similar to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission model can explain the current transport well in this region. Below 200 K, the bulk carriers start to freeze out and the induced oxygen vacancies in the interface region, probably due to the formation of silver oxide at the Ag–ZnO interface, will influence significantly the current transport by creating very thin interfacial layer that is susceptible to electron tunneling.

Semiconductor device and production method therefor

Abstract: An object of the invention is to provide a method for producing a conductive member having low electrical resistance, and the conductive member is obtained using a low-cost stable conductive material composition that does not contain an adhesive A method for producing a semiconductor device in which silver or silver oxide provided on a surface of a base and silver or silver oxide provided on a surface of a semiconductor element are bonded, includes the steps of arranging a semiconductor element on a base such that silver or silver oxide provided on a surface of the semiconductor element is in contact with silver or silver oxide provided on a surface of the base, and bonding the semiconductor element and the base by applying heat having a temperature of 200 to 900° C to the semiconductor device and the base

UV curing antibiotic coating and preparation thereof

Abstract: The invention discloses a UV-curable antimicrobial coating, the components of which are as follows: bisphenol A type epoxy acrylate EA; aliphatic PUA; special functional group acrylate PA; TPGDA; TMPTA; photoinitiators; nano acrylate; oxidized silver; and auxiliaries. The preparation method comprises the following steps of: step one, synthesizing special functional group heterocyclic compound PA and later adding phosphorus pentoxide to acrylic acid hydroxy esters so as to react with hydroxyl piperidine and then prepare special functional group heterocyclic compound PA; and step two, taking each component according to the formula, stirring and mixing each component so as to carry out dispersion at the speed of 900 to 1200r per min, then adding silver oxide and photoinitiators after being dispersed evenly, and finally obtaining UV-curable antimicrobial coating through dispersion. The UV-curable antimicrobial coating prepared by the invention has good anti-bacterial effect. As the self-prepared special functional group acrylate PA, the nano acrylate and the silver oxide are added, after UV-curable film-forming, the anti-coli rate can achieve over 99 percent and the anti-staphylococcal rate thereof achieves over 99 percent, and the effectiveness is long.

An in situ temperature‐programmed XPS study of the surface chemical reactions of thiophene with Ag/titania

Abstract: The Ag/titania sorbent for the ultradeep desulfurization of liquid fuels was characterized by electron spin resonance and was found to contain nearly the stoichiometric titania, without significant concentration of Ti 3+ or the reactive oxygen species. The surface chemical reactions of thiophene adsorbed on the Ag/titania were studied by temperature-programmed XPS from 25 to 525 °C upon in situ thermal annealing in high vacuum and in situ oxidation by oxygen gas. The titania support is not chemically reactive under those conditions. Silver oxide in the Ag/titania sorbent is converted to Ag 2 S without formation of the transient surface sulfates or sulfites and is further oxidized by molecular oxygen.

Effect of aging on optical properties of bimetallic sensor chips

Abstract: Bimetallic sliver/gold sensor chips are attractive since they combine the advantages of both silver and gold layers. Optical properties of the bimetallic sensor chips show significant aging effects. Surface plasmon resonance (SPR) curves were produced on an SPR device and the time dependence of aging on SPR curves was studied. The results show that resonance angle and full width at half maximum (FWHM) of response curves increase with the aging time after film deposition. The performance of the sensor chips in terms of intrinsic sensitivity (IS) degrades with aging time. The underlying mechanism of the aging effect is explained as the growth of a silver oxide layer between gold and silver during the aging process.

A weak mixed mobile ion effect in vanadium–tellurite oxide glass modified by silver and lithium cations

Abstract: The effect of the partial replacement of lithium oxide by silver oxide in a glassy vanadium–molybdenum–tellurite oxides matrix is analyzed by means of impedance spectroscopy. We find that a weak mixed mobile ion effect (MMIE) is due to the different kind of modifications silver and lithium oxides induce in the glass of formula 0.7[x Ag2O (1 − x) Li2O] 0.3[0.5 V2O5 0.5 MoO3] 2 TeO2.

Construction of a monoanionic S,N,S-pincer ligand with a pyrrole core by sequential [1,2] phospho-Fries rearrangement. Characterization of palladium and silver coordination complexes.

Abstract: The synthesis of an S,NH,S-pincer ligand possessing a pyrrole core and two O,O-diethylthiophosphonyl groups to design PS lateral coordination sites is reported. The synthetic procedure to produce this ligand makes use of the nitrogen atom of the pyrrole heterocycle to successively functionalize the ortho-positions with the two O,O-diethylthiophosphonyl moieties. The ortho-functionalization arises from a repetition of a [1,2] base-induced rearrangement allowing the transformation of O,O-diethyl-N-pyrollylthiophosphoramidate to ortho-thiophosphonate. The coordination properties of this tridentate S,NH,S-ligand have been investigated with silver and palladium metals. Reaction of the monoanionic S,N,S-pincer ligand 4 (O,O,O,O-tetraethylpyrrol-2,5-yl-dithiophosphonate) with PdCl2(MeCN)2 at room temperature in the presence of triethylamine gives rise to the formation of the η3-complex [Pd(η3-4′)Cl] 5. Ligand 4 also reacts with silver oxide in dichloromethane to produce complex 6 which, in the solid state, exists as a tetramer involving an almost linear arrangement of four silver atoms.

Determination of nanometric Ag2O film thickness by surface plasmon resonance and optical waveguide mode coupling techniques

Abstract: There is a continuing need for measuring nanometric film thicknesses for a wide variety of industrial and scientific purposes. Kretschmann-type sensors are well-known multilayer nanometric sensing devices. This work is focused on two objectives: firstly, the design of an Ag2O Kretschmann sensor and, secondly, the development of a measurement protocol for determining silver oxide thickness when a silver film of given initial thickness is gradually converted into silver oxide by exposure to a controlled oxygen-rich atmosphere. The particular characteristics of the reflectivity curves of this multilayer structure are studied for both p- and s-wave polarization as a function of the incidence angle and layer thickness. In the former, the surface plasmon resonance (SPR) dip position as well as its FWHM depends strongly on silver oxide thickness. For s-wave polarization, a broad dip due to optical waveguide mode coupling is observed for angles larger than the total internal reflection (TIR) angle when sufficiently large silver oxide thicknesses are studied. Besides, reflectivity at fixed angles for both polarizations was studied as a function of the silver oxide layer. Each of these relations may be represented by different continuous functions defined for successive ranges that can be used as calibration curves. Taking into account all these features, a measurement protocol is proposed for determining silver oxide thickness when a 45 nm initial silver film is gradually converted into silver oxide by exposure to an oxygen-rich atmosphere. This new approach is an alternative to the traditional methods of full angular interrogation in the Kretschmann configuration. Based on this procedure, it is possible to measure Ag2O thickness in the range 0–70 nm.

Electronic member, electronic part and manufacturing method therefor

Abstract: When silver oxide is reduced to silver, a large number of cores of metallic silver are formed inside the silver oxide. Then, the silver oxide is reduced in a manner of being hollowed out while its original outer configuration is being maintained. As a result, the curvature of the silver generated becomes larger. The utilization of this microscopic-particle implementation mechanism allows accomplishment of the bonding even if the silver oxide is supplied not in a particle-like configuration, but in a closely-packed layer-like configuration. In the present invention, there is provided an electronic member including an electrode for inputting/outputting an electrical signal, or a connection terminal for establishing a connection with the electrical signal, wherein the uppermost surface of the electrode or the connection terminal is a silver-oxide layer.

Controlling the formation of silver nanoparticles on silica by photochemical deposition and other means.

Abstract: Silver nanoparticles (Ag-NP) on silica were produced in aqueous solution by deposition of silver on colloidal silica in a small cuvette using radiation from a xenon-mercury lamp. Ag-NP were also synthesized on a much larger scale with low-level, long-term visible light irradiation for several months. In both cases, the nanoparticle production was monitored by the appearance of the surface plasmon resonance (SPR) band at around 410 nm. The growth of the nanoparticles was directly related to the time exposed to radiation, which could be tracked spectrophotometrically over time. We also investigated the possibilities of rapid nanoparticle production without the assistance of radiation though silver oxide by adding alkali hydroxide, which is a relatively unexplored approach for syntheses of Ag-NP on silica. The SPR absorption of Ag-NP was used as a tool in evaluating the size and shape of the resulting nanoparticles along with dynamic light scattering and transmission electron microscopy data. In order to better utilize and understand Ag-NP, we present various ways to control their production through initial concentration adjustments, irradiation effects, gravitational fractionation, sonication and silver oxide formation.

Light-induced EMF in silver-palladium film resistors

Abstract: We have studied the generation of nanosecond emf pulses in silver-palladium film resistors under the action of radiation of a Q-switched laser. The samples were fabricated using the technology of thick film resistors on dielectric substrates, based on fusing a resistive paste that contains palladium, silver oxide, glass, and an organic binder into the substrate at 880 K. The amplitude of detected pulses exhibits linear growth with the power of incident laser radiation, depends on the angle of light incidence (vanishes at the normal incidence) onto the film and the angle of film rotation about the normal to its surface, and changes its sign with that of the incidence angle. The duration of the generated emf pulses is several times that of the incident laser pulses. The signal is not of a thermoelectric nature and can be related to the current generation by means of the surface photogalvanic effect and the photon quasi-momentum transfer to charge carriers during light absorption by the film material.

Semiconductor device and method of manufacturing same

Abstract: A method of manufacturing a conductive material which generates a low electrical resistance value and which is obtained by using an inexpensive and stable composition for conductive materials that does not include an adhesive. The method manufactures a semiconductor device which is formed by bonding the silver or silver oxide deposited on the surface of a base to the silver or silver oxide deposited on the surface of a semiconductor component. The method manufactures the semiconductor device by means of a step arranging the semiconductor component on the base so that the silver or silver oxide deposited on the surface of the former contacts the silver or silver oxide deposited on the surface of the latter, a step applying pressure or ultrasonic vibration to the semiconductor component or base to temporarily bond the semiconductor component to the base, and a step applying a temperature of 150°C to 900°C to the semiconductor component and base to permanently bond the semiconductor component to the base.

Semiconductor device and method for manufacturing same

Abstract: Disclosed is a method for producing a conductive material which has a low electrical resistivity and can be obtained using a low-cost stable conductive material composition that does not contain an adhesive. Also disclosed is a method for manufacturing a semiconductor device in which silver or silver oxide provided on the surface of a base is joined with silver or silver oxide provided on the surface of a semiconductor element. The semiconductor device is produced by a procedure including a step wherein the base and the semiconductor element are arranged so that the silver or silver oxide provided on the surface of the semiconductor element is in contact with the silver or silver oxide provided on the surface of the base, and a step wherein the semiconductor element and the base are joined together by applying a heat of 200-900°C to the semiconductor element or the base.

Effect of deposition temperature on the physical properties of RF magnetron sputtered Ag-Cu-O films with various Cu to Ag ratios

Abstract: Thin films of Ag-Cu-O were deposited on glass substrates held at various temperatures in the 303-523 K range by RF magnetron sputtering of Ag 90 Cu 10 , Ag 80 Cu 20 and Ag 70 Cu 30 , and elemental copper and silver targets in an oxygen partial pressure of 2 x 10- 2 Pa and sputtering pressure of 4 Pa. The deposited films were characterised by energy dispersive X-ray analysis, X-ray diffraction (XRD), atomic force microscopy, UV-Vis-NIR spectroscopy and employing four-point probe method. The atomic ratio of Cu/Ag in the films formed at 303 K was in correlation with the composition of the starting sputter targets. The increase in substrate temperature induced the decomposition of the Ag-Cu-O films into a mixture of metallic silver and copper oxide. The electrical resistivities of silver oxide and copper oxide films formed at 303 K were 3 x 10 -3 Ω cm and 29 Ω cm, respectively. The electrical resistivity of the films formed with Ag 70 Cu 30 target at 303 K was 8.2 Ω cm and it decreased to 2.4 Ω cm with increase in substrate temperature to 523 K due to structural changes in the films. The optical band gap of the Ag-Cu-O films formed a: 303 K increased from 1.60 to 1.95 eV with the increase of copper to silver atomic ratio from 0.10 to 0.30 in the films. The optical band gap of the films formed with Ag 70 Cu 30 targe: increased from 1.95 to 2.15 eV with the increase in substrate temperature from 303 to 523 K, respectively.