Showing papers on "Oxide published in 1977"
TL;DR: In this article, the binding energy of the Zn 2P/sub 3/2/ electron in sludge was found to be 3.5 +- 0.1 on the Pauling scale.
Abstract: Electron Spectroscopy for Chemical Analysis (ESCA) was used to provide information concerning the chemical bonding of zinc and copper present in the sludge obtained from the Dayton, Ohio sewage treatment plant. The binding energy of the Zn 2P/sub 3/2/ electron in sludge when placed under a vacuum of 10/sup -7/ Torr was 1023.8 +- 0.2 eV and the binding energy of the Cu 2p/sub 3/2/ electron in the sludge under similar conditions was 937.2 +- 0.3 eV. These energies are characteristic of both Zn and Cu being in the positive two oxidation state. The electronegativity of the ligand attached to either of these metals was found to be 3.5 +- 0.1 on the Pauling scale. This indicates that Zn and Cu exist in similar compounds, that the ligand binding site is oxygen, and that the possible compounds include carbonate, carboxylate, phosphate, nitrate, silicate, and/or oxide. ESCA, when used in conjunction with other methods, offers excellent potential for more specifically identifying the chemical form of metal in sludge or sludge mixtures.
438 citations
TL;DR: In this article, the photoelectrochemical properties of polycrystalline metal oxide electrodes were investigated, including tunneling effects and the operation of Fe/sub 2/O/sub 3/ in a solar cell.
Abstract: An investigation was made of the photoelectrochemical properties of several polycrystalline metal oxide electrodes prepared by chemical vapor deposition, direct oxidation of the metal or heating of suitable metal salt solutions. Further data are given on the behavior of the previously discussed TiO/sub 2/ and Fe/sub 2/O/sub 3/ electrodes including tunneling effects and the operation of the Fe/sub 2/O/sub 3/ in a solar cell. Other n-type materials studied were V/sub 2/O/sub 5/, WO/sub 3/, and PbO. WO/sub 3/ and PbO showed good anodic photocurrents but only WO/sub 3/ appeared stable. Bi/sub 2/O/sub 3/ showed both n- and p-type photocurrents, but had a poor stability. CuO produced a good cathodic photocurrent (indicating p-type behavior) with a photoresponse at wavelengths of 700 nm and below. Two other oxides, Cr/sub 2/O/sub 3/ and CoO, exhibited small p-type photoeffects.
400 citations
TL;DR: In this article, conditions for effective intrinsic gettering by oxide precipitate induced dislocations, which is suggested as an important mechanism in explaining device leakage limited yield enhancement due to oxygen in Czochralski-grown Si wafers, are examined.
Abstract: Conditions for effective intrinsic gettering by oxide precipitate induced dislocations, which we suggest as an important mechanism in explaining device leakage limited yield enhancement due to oxygen in Czochralski‐grown Si wafers, are examined. The effectiveness of this mechanism is demonstrated.
331 citations
TL;DR: In this article, the compositions of the alloy surface and the surface oxide on mechanically polished iron-chromium alloys were studied using the XPS technique, and the results showed no enrichment of chromium or iron either in the oxide layer or the Alloy surface.
327 citations
TL;DR: In this paper, it has been shown that the long-term chemical resistance of a glass is mainly determined by the thermodynamic activity and stability of its component oxides in aqueous solutions.
Abstract: The various hypotheses regarding corrosion of oxide glass surface by aqueous solutions have been reviewed. It has been shown that the long-term chemical resistance of a glass is mainly determined by the thermodynamic activity and stability of its component oxides in aqueous solutions. The stability of different oxides commonly used in glass-making like SiO2, ZnO, PbO, Al2O3, ZrO2 etc. in aqueous solutions of different pH has been calculated with available thermodynamic data, and these have been discussed in relation to the corrosion behaviour of glasses (prepared with these oxides) in aqueous solutions of various pH range. Suitable experimental results have been furnished to justify the importance of thermodynamic stability of component oxides of a glass on its corrosion behaviour in aqueous solutions.
307 citations
TL;DR: In this paper, photoelectron spectroscopic studies of Ni(111), Ni(100) and Ni(110) surfaces were conducted to investigate the oxidation process of NiO.
292 citations
TL;DR: In this article, an experimental study of the electrical conduction mechanisms in a thin-film (cermet) resistor is presented. But the authors focus on the electrical transport properties of the resistors.
Abstract: This paper presents an experimental study of the electrical conduction mechanisms in thick‐film (cermet) resistor. The resistors were made from one custom and three commercially formulated inks with sheet resistivities ranging from 102 to 106 Ω/⧠ in decade increments. Their microstructure and composition have been examined using optical and scanning electron microscopy, electron microprobe analysis, x‐ray diffraction, and various chemical analyses. This portion of our study shows that the resistors are heterogeneous mixtures of metallic metal oxide particles (∼4×10−5 cm in diameter) and a lead silicate glass. The metal oxide particles are ruthenium containing pyrochlores, and are joined to form a continuous three‐dimensional network of chain segments. The principal experimental work reported here is an extensive study of the electrical transport properties of the resistors. The temperature dependence of conductance has been measured from 1.2 to 400 K, and two features common to all resistors are found. Th...
268 citations
TL;DR: In this paper, curvature measurements from 25 to 1075°C were used to demonstrate viscous flow of thermally grown SiO2 at temperatures as low as 960°C.
Abstract: Wafer curvature measurements from 25 to 1075 °C are used to demonstrate viscous flow of thermally grown SiO2 at temperatures as low as 960 °C. Both O2‐ and steam‐grown oxides are examined and found to have viscosities similar to synthetic fused silica. It is recommended that high‐temperature Si device processing involving SiO2 be held to below 960 or even 925 °C, after oxide growth to avoid viscous flow and the accompanying structural damage in the oxide. This recommendation holds particularly for device technologies where resistance to ionizing radiation is important. The measurements also demonstrate that gross structural damage resides in the Si beneath steam‐grown oxide.
253 citations
TL;DR: In this paper, the authors present a physical description of the action of ZnO varistors, which are complex ceramic bodies of zinc oxide grains sintered in an oxide flux; their conductivity is very low at low voltage, but becomes high after a certain breakdown voltage is reached.
Abstract: This paper presents a physical description of the action of ZnO varistors, which are complex ceramic bodies of ZnO grains sintered in an oxide flux; their conductivity is very low at low voltage, but becomes high after a certain breakdown voltage is reached. It is found that depletion layers in the ZnO adjacent to the intergranular layers of oxide flux are the principal barrier to conduction at low voltage. These depletion layers are formed because electron traps in the intergranular layer absorb electrons from the ZnO, and the oxide flux itself is found to be more conductive than the neighboring barriers; conduction within the flux is observed at low temperatures. Electrical breakdown is associated with the completion of trap filling in thin regions of the intergranular layer. This model is supported by a wide range of physical phenomena.
236 citations
TL;DR: In this article, the electrochemical properties of semiconducting anodes of TiO2, SrTiO3, BaTiO 3, Fe2O3 and CdO were determined in photo assisted electrolysis of water.
Abstract: The electrochemical properties of semiconducting anodes of TiO2, SrTiO3, BaTiO3, Fe2O3, CdO, CdFe2O4, WO3, PbFe12O19, Pb2Ti1.5W0.5O6.5, Hg2Ta2O7, and Hg2Nb2O7 in photoassisted electrolysis of water were determined. All of these oxides formed a rectifying junction with the electrolyte and anodic photocurrents were generated only with larger‐than‐band‐gap illumination. For Fe2O3, the optical absorption spectrum was different from the photoelectrochemical spectrum due to crystal field transitions. These oxides were found to be stable over certain range of pH. In a given electrolyte, the flatband potential Vfb varied linearly with the band gap. A good correlation was obtained between Vfb and the heat of formation of the oxide per metal atom per metal‐oxygen bond, but not between Vfb and the calculated Fermi energy of the oxide. This suggests that a semiconductor‐electrolyte interface may be approximated by a semiconductor‐metal junction where the barrier height is determined by the heat of formation of the me...
235 citations
TL;DR: In this paper, the nonlinearity was attributed to the potential barrier due to the depletion layer formed in the interfacial region of the ZnO grainboundaries doped with Co atoms.
Abstract: Zinc oxide ceramics containing rare earth metal oxide and cobalt oxide which exhibit non-ohmic current-voltage characteristics were studied. The nonlinearity was similar to that of the zinc oxide varistor containing Bi2O3 and other additives. According to microstructural observations, the intergranular layer of the ceramics was found to be a rare earth metal oxide compound without Zn and Co atoms, and its thickness was expected to be less than 100 A. The nonlinear characteristics are attributed to the potential barrier due to the depletion layer formed in the interfacial region of the ZnO grainboundaries doped with Co atoms. Qualitative analysis of capacitance-voltage relations confirmed this model.
TL;DR: In this paper, the mechanism of field-assisted pore formation in 15% wt aqueous solutions was studied by O18 tracing techniques and it was found that the initial number of O18 atoms per square centimeter is conserved to within 2% and the major part of the oxygen of the initial base layer is located on the top of the duplex film with the same O18 isotopic concentration.
Abstract: The mechanism of field‐assisted pore formation in 15% wt aqueous solutions was studied by O18 tracing techniques. Compact base layers were first formed in an O18 labeled solution and further oxidized in a nonlabeled solution, leading to field‐assisted pore formation. The O18 content and depth distribution was measured in these duplex films. It was found that the initial number of O18 atoms per square centimeter is conserved to within 2% and that the major part of the oxygen of the initial base layer is located on the top of the duplex film with the same O18 isotopic concentration. This observation shows clearly that the pore formation does not take place through a simple oxide dissolution process whether chemical or field assisted. Pore formation consists of some kind of oxide decomposition involving only cation transfer into the solution. The values of the cationic and anionic currents are calculated. Possible mechanisms for ion movement are discussed.
TL;DR: In this article, the role of the metal/metal oxide or the lower metal oxide/higher metal oxide couple in determining the minimum voltage required for the evolution of oxygen is emphasized, together with other essential requirements such as electrical resistivity, electrode microstructure, corrosion resistance and catalytic properties.
TL;DR: In this paper, a thermal decomposition of manganese nitrate solution on a titanium or a platinum substrate was investigated mainly in 1N H2SO4 and 1N KOH.
TL;DR: In this paper, the surface oxides produced from potentiostatic and galvanostatic oxidation of Pt electrodes in HClO4 and H2SO4 were examined using X-ray photoelectron spectroscopy.
TL;DR: In this article, surface parameters and thermal dehydration/rehydration behavior of the La(OH)3/La2O3 system have been examined with a view toward establishing suitable methods for preparing and characterizing catalytic forms of the rare earth oxides.
TL;DR: In this paper, the electrochromic optical absorption of mixed-oxide WO3/MoO3 amorphous films occurs at higher energy than either pure oxide alone and the systematics of the energy shifts as a function of MoO3 concentration and coloration density is determined.
Abstract: The electrochromic optical absorption of mixed‐oxide WO3/MoO3 amorphous films occurs at higher energy than either pure oxide alone. The systematics of the energy shifts as a function of MoO3 concentration and coloration density is determined. The data is explained by the intervalency charge‐transfer model if we assume that electrons trapped at Mo6+ ions lie 0.73 eV deeper than electrons on W6+ ions. Measurements of electron diffusion in mixed oxides support this hypothesis. The maximum absorption peak of mixed oxides is 2.15 eV compared with 1.4 eV for WO3. This is close to the peak in eye sensitivity, thereby leading to improved electrochromic display devices.
TL;DR: In this article, the surface composition of unstabilized austenitic stainless steel (En 58A) was determined by Auger electron spectroscopy and measurements carried out when oxidation was complete were made using energy dispersive X-ray analysis and electron microprobe analysis.
TL;DR: In this article, an independent iron-titanium oxide geothermometer and oxygen barometer from the experimental data of Buddington and Lindsley (1964) are presented graphically for coexisting ilmenite solid solutions and magnetite solid solution in the system FeO-Fe2O3-TiO2.
Abstract: Equilibrium thermodynamic methods are used to develop an independent iron-titanium oxide geothermometer and oxygen barometer from the experimental data of Buddington and Lindsley (1964). The geothermometer and oxygen barometer are presented graphically for coexisting ilmenite solid solution and magnetite solid solution in the system FeO-Fe2O3-TiO2. Equations are also given for calculating temperature and oxygen activity for natural coexisting iron-titanium oxides containing other components. Large departures in composition from the system FeO-Fe2O3-TiO3 result in large uncertainties in the calculated temperature and activity of oxygen.
TL;DR: The point defect equilibria of cobaltous oxide (Coi_äO) as a function of temperature and oxygen potential are analyzed in this paper, where majority point defects are electron holes and differently charged vacancies in the cation sublattice.
Abstract: The point defect equilibria of cobaltous oxide (Coi_äO) as a function of temperature and oxygen potential are analyzed. Majority point defects are electron holes and differently charged vacancies in the cation sublattice. On the basis of the derived defect model it is possible to quantitatively describe literature data for non-stoichiometry, electrical conductivity and cation tracer diffusion. Additional cation tracer diffusion coefficients were measured at temperatures between 1000 and 1400 °C as a function of the oxygen activity covering the entire 1 atm stability range of this oxide.
TL;DR: In this paper, the surface oxides on thin (200-250 A) vacuum-deposition titanium films were formed under conditions of linear potential scan in 1 N KClO4, 1 N HCLO4 and 1 n H2SO4, with the higher oxide states predominating on the electrochemically oxidized films.
TL;DR: In this article, the influence of a vacancy supersaturation on the kinetics of oxidation is discussed in detail, but the effects are shown to be small in practical cases, and the main consequence of vacancy injection is the eventual breakdown of the initial scale and subsequent growth of a duplex porous oxide.
TL;DR: In this article, the authors studied high temperature oxidation in air of Fe13Cr-x Al alloys containing up to 4.5 Al in the temperature range 680-980°C.
TL;DR: In this paper, the field and temperature dependence of the interface state density as a function of time following pulsed e-beam irradiation, and the dose dependence of interface-state density following steady state Co60 irradiation were examined in MOS capacitors with both hardened dry and wet gate oxides.
Abstract: The field and temperature dependence of the interface-state density as a function of time following pulsed e-beam irradiation, and the dose dependence of the interface-state density following steady state Co60 irradiation were examined in MOS capacitors with both hardened dry and wet (pyrogenic) gate oxides. From the results of the pulsed e-beam experiment, we show that in the wet oxide the electric field affects the time scale for the buildup of interface states as well as the final or saturation value of interface states at late times (~105 s), but that in the dry oxide there is no marked field dependence. For the wet oxide, we observed that temperature affects only the time scale for the buildup of interface states. From total-dose Co60 measurements, we report a power law dependence on dose, D0.65, for both wet and dry oxide capacitors. The buildup of interface states in the wet-oxide capacitors is considerably larger than in the dry.
TL;DR: In this paper, surface regions of GaAs crystals treated by removal of anodically grown oxide layers with aqueous HCl and NH4OH solutions were investigated with Auger electron and x-ray photoemission spectroscopies.
Abstract: Surface regions of GaAs crystals treated by removal of anodically grown oxide layers with aqueous HCl and NH4OH solutions were investigated with Auger electron and x‐ray photoemission spectroscopies. After treatment and air exposure, the surfaces were covered with about 10 A of oxide consisting of Ga2O3 and As2O3. Semiquantitative estimates of the surface compositions revealed that after removal of the anodic oxide with HCl etch, the surfaces contained excess As, up to 10 A of carbon contamination, and small quantities of S, Cl, Ca, and N. The excess As originates from a pileup of elemental As at the oxide/GaAs interface during oxide growth. The As‐rich surface is highly reactive and readsorbs contaminants from the air and/or the etch‐rinsing solutions. By contrast, after removal of the anodic oxide with NH4OH etch, the surfaces contained much less excess As, carbon, and contaminants. The most reproducible results were obtained by following a procedure developed in this work which produced surfaces contai...
Patent•
04 May 1977
TL;DR: In this article, a method for electrodepositing ductile, bright, well leveled copper deposits from an aqueous acidic copper plating bath having dissolved therein from about 0.04 to about 1000 milligrams per liter of a poly (alkanol quaternary ammonium salt) formed as the reaction product of polyalkanolamine with an alkylating or quaternization agent.
Abstract: A composition and method for electrodepositing ductile, bright, well leveled copper deposits from an aqueous acidic copper plating bath having dissolved therein from about 0.04 to about 1000 milligrams per liter of a poly (alkanol quaternary ammonium salt) formed as the reaction product of a polyalkanolamine with an alkylating or quaternization agent. The polyalkanolamine constituent typically is formed as the reaction product of a polyalkylenimine (e.g. polyethylenimine) with an alkylene oxide.
TL;DR: In this paper, the results for oxygen evolution are discussed in terms of electrochemically generated unstable surface oxides whose decomposition is catalysed by protons in acid, and hydroxide ions in base.
Abstract: The electrocatalytic behaviour of Ti-supported RuO2, prepared by thermal decomposition of RuCl3, as substrate for oxygen evolution was investigated by a variety of techniques. B.E.T. adsorption experiments showed that the RuO2 layers are highly porous with large surface area values which, however, decrease rapidly as the annealing temperature increases above ∼ 300°C. Both the charge involved in the cyclic voltammograms and the oxygen evolution rates are dependent on the true (rather than apparent) area of these electrode surfaces, and also on the pH of the solution. The results for oxygen evolution are discussed in terms of electrochemically generated unstable surface oxides whose decomposition is catalysed by protons in acid, and hydroxide ions in base. The lower reactivity of the oxide at intermediate pH value is attributed on the one hand to loss of protons by OH groups, resulting in oxygen bridging, and on the other to lack of enhanced coordination of surface ruthenium species by OH– ions, which in this pH region are present only at low activity. The charge associated with voltammetric sweeps is accounted for in terms of surface redox processes rather than bulk penetration of protons into the oxide. The need for surface area measurements as a guide to the interpretation of the electrochemical data in the case of these oxide systems is stressed.
TL;DR: In this article, the presence of the asperities is strongly correlated with the oxide conductivity, as controlled by the oxidation temperature of polycrystalline silicon, and direct evidence of these asperity is shown in SEM micrographs.
Abstract: High conductivity observed in oxides grown on polycrystalline silicon has been previously speculated as being due to asperities on the silicon surface, which enhance the oxide field. Direct evidence of these asperities is shown here in SEM micrographs. The presence of the asperities is strongly correlated with the oxide conductivity (as controlled by the oxidation temperature).