Showing papers on "Bismuth published in 1985"
TL;DR: A flow injection technique was applied to hydride-generation atomic absorption spectrometry as discussed by the authors, where gas segmentation was found to be effective in minimizing the broadening of a sample zone without an increase of noise levels.
Abstract: A flow injection technique was applied to hydride-generation atomic absorption spectrometry. For the present reaction, gas segmentation was found to be effective in minimizing the broadening of a sample zone without an increase of noise levels. When 0.5 mL of samples was used, arsenic, antimony, bismuth, selenium, and tellurium could be determined with the detection limits (S/N = 3) of 0.04-0.3 ng and relative standard deviations better than 2.5%. About 120 samples could be determined within an hour. These elements in several NBS SRMs were determined.
133 citations
TL;DR: In this paper, the effect of small additions of Bi2O3 to zinc electrodes has been studied using chronopotentiometry, cyclic voltammetry, and polarization studies.
117 citations
TL;DR: In this article, the properties of ZnWO4, bismuth doped ZnO4 and antimon doped WO4 were studied. Decay time, light yield and their temperature dependence were reported.
105 citations
Patent•
02 Apr 1985
TL;DR: In this paper, an improved method utilizing a dopant selected from the group consisting of sulfur, selenium, tellurium, phosphorous, arsenic, antimony, bismuth and mixtures thereof, is now available by which a considerable increase of the growth rate of the layer as well as optimal properties regarding evenness and thickness have been obtained, making the product better suited for cutting operation.
Abstract: In coating cemented carbide or ceramics, with thin, wear resistant layers of ceramic oxide, particularly aluminum oxide, by CVD, it has been very difficult to make sufficiently even layers and to obtain desired thickness of the layer within reasonable coating times. According to the invention an improved method utilizing a dopant selected from the group consisting of sulfur, selenium, tellurium, phosphorous, arsenic, antimony, bismuth and mixtures thereof, is now available by which a considerable increase of the growth rate of the layer as well as optimal properties regarding evenness and thickness of the layer have been obtained, making the product better suited for cutting operation.
66 citations
TL;DR: In the presence of metallic bismuth, allyl halides were found to react with aldehydes under mild conditions to give the corresponding homoallylic alcohols in good yields.
62 citations
TL;DR: In this article, perfect crystal silicon samples implanted with 60 KeV Bi atoms along the [110] surface normal direction were analyzed with X-ray standing waves and two reflection orders, (220 and 440) were used with synchrontron radiation to study systematically the impurity distribution function at 5 different doses ranging from 0.6 to 10×1014 Bi atoms/cm2.
Abstract: Perfect crystal silicon samples implanted with 60 KeV Bi atoms along the [110] surface normal direction were analyzed with X-ray standing waves. Two reflection orders, (220) and (440) were used with synchrontron radiation to study systematically the impurity distribution function at 5 different doses ranging from 0.6 to 10×1014 Bi atoms/cm2. The analysis reveals the substitutional Bi position connected with a lattice expansion and the formation of precipitates at higher Bi doses as well as estimates for the Bi vibrational amplitude.
60 citations
TL;DR: In this article, the design and performance characteristics of a continuous-flow vapor generation accessory for atomic absorption spectrophotometry are reported, which provides analytical sensitivity for mercury, arsenic, selenium, antimony, bismuth, tellurium and tin equal or superior to that of a batch-type vapor generation device.
Abstract: The design and performance characteristics of a continuous-flow vapor generation accessory for atomic absorption spectrophotometry are reported. When used with a conventional atomic absorption spectrophotometer, the accessory provides analytical sensitivity for mercury, arsenic, selenium, antimony, bismuth, tellurium, and tin equal or superior to that of a batch-type vapor generation device. Sample presentation, sample consumption, precision of measurement, and simplicity of operation are similar to those of flame atomic absorption with a pneumatic nebulizer. Details of the construction of the continuous-flow manifold, gas/liquid separator, and absorption cells are discussed, and the effects of reagent concentrations and carrier gas flow rates are shown. Characteristic concentrations and analytical curves for the above elements are also presented.
56 citations
TL;DR: Under basic conditions well defined pentavalent intermediates have been isolated and fully characterised and their decomposition gives only ortho-C-phenylation, seen under neutral or acidic conditions.
Abstract: The phenylation of a variety of phenols by pentavalent bismuth reagents under neutral, acid and basic conditions has been investigated. Under basic conditions well defined pentavalent intermediates have been isolated and fully characterised. Their decomposition gives only ortho-C-phenylation (except in the case of a p-nitrophenol derivative). O-Phenylation is seen under neutral or acidic conditions. Another mechanism is proposed to explain this reaction with no pentavalent bismuth intermediate.
53 citations
50 citations
TL;DR: In this article, the piezoelectric properties of the grain-oriented Na0.5Bi4.5Ti4O15 (NBT) ceramic, belong to the bismuth layer-structured ferroelectric (BLSF) ceramics are studied from applicational viewpoints on grain orientation prepared by the hot-forging (H.F.) method.
Abstract: Piezoelectric properties of the grain-oriented Na0.5Bi4.5Ti4O15 (NBT) ceramic, belong to the bismuth layerstructured ferroelectric (BLSF) ceramics are studied from applicational viewpoints on grain orientation prepared by the hot-forging (H.F.) method. The MnCO3 (0.1 wt%) doped NBT (NBT+Mn(0.1)) ceramic can stand the high temperature poling process, because of the high resistivity. The grain orientation (H.F.) makes the piezoelectric properties of NBT+Mn(0.1) ceramic much more pronounced than those of the non-oriented (O.F.) ceramic. Coupling factors k33 and k15, along with piezoelectric constants d33, d15, g33 and g15, of the H. F. NBT+Mn(0.1) ceramic are enhanced, and their anisotropies in k33/k31 and k15/k24 are emphasized. A bulk wave delay line oscillator using the ceramic substrate is demonstrated.
46 citations
Patent•
28 Nov 1985TL;DR: In this article, the gas phase catalytic oxidation of isobutylene or t-butanol at high temperature using molecular oxygen in the presence of catalyst consisting of molybdenum, tungsten, bismuth, iron, nickel, antimony, and an alkali metal, to which zinc or lead is added, and further phosphorus or boron, and magnesium, cobalt, manganese, or tin are added.
Abstract: The present invention provides a process for the production of methacrolein and methacrylic acid by the gas phase catalytic oxidation of isobutylene or t-butanol at high temperature using molecular oxygen in the presence of catalyst consisting of molybdenum, tungsten, bismuth, iron, nickel, antimony, and an alkali metal, to which zinc or lead is added, and further phosphorus or boron, and magnesium, cobalt, manganese, or tin are added.
TL;DR: In this article, the effect of trace impurities, particularly bismuth and boron, on etching morphology and capacitance of aluminum electrolytic capacitor foil was investigated.
Abstract: An investigation was made as to the effect of trace impurities, particularly bismuth and boron, on etching morphology and capacitance of aluminum electrolytic capacitor foil. It was found that as little as 2 wt‐ppm bismuth in foil strongly accelerated surface etching, inhibited tunneling, and consequently lowered capacitance. 3 wt‐ppm boron also enhanced surface etching, but lowered capacitance less than bismuth. The reason for these results was considered
TL;DR: In this paper, laser-excited techniques were used to investigate the optical properties of bismuth germanate crystals, and the absorption and emission mechanism at room temperature involved a thermally activated energy migration, and at low temperature localized emitting centers.
TL;DR: In this article, the binding energies of the charring products for lead and bismuth in the presence or absence of palladium obtained at the initial stage of atomization were measured.
TL;DR: In this paper, a two-layer model was used to explain the properties of the materials in terms of a two layer model and the observed behaviour was attributed to cluster formation at the grain boundaries.
Abstract: Zinc-substituted lithium ferrites Li 0.5− z 2 Zn z Fe 2.5− z 2 O 4 with z varying from 0 to 0.7 were prepared. Small amounts of bismuth oxide were used to reduce the sintering temperature. In dense materials prepared in this way Bi 2 O 3 segregates at grain boundaries and the grains consist of only the basic ferrite. Electrical properties such as the resistivity, the dielectric constant and the loss factor were measured over a wide frequency range. The parameters obtained at direct current and high frequencies were used to explain the properties of the materials in terms of a two-layer model. In samples with z > 0.4 the observed behaviour was attributed to cluster formation at the grain boundaries.
TL;DR: The spectrum of neutral bismuth has been studied in the infrared region by means of the Fourier transform spectrometer at the Laboratoire Aime Cotton, Orsay, France as mentioned in this paper.
Abstract: The spectrum of neutral bismuth has been studied in the infrared region by means of the Fourier-transform spectrometer at the Laboratoire Aime Cotton, Orsay, France. A microwave-excited discharge tube containing bismuth iodide was used as the light source. A total of 37 hyperfine structures was studied. Precise measurements of the center of gravity of the structures give energy levels with an error less than 0.005 cm−1. Complete analysis of these hyperfine structures resulted in the determination of the magnetic-dipole and the electric-quadrupole interaction constants for 10 even and 12 odd levels. The present results have increased the number of newly classified lines to 78, as compared with 28 reported in our earlier work [ J. Opt. Soc. Am.72, 589 ( 1982)]. The analysis has also resulted in the confirmation and the assignment of many J values, improved values of energy levels, and two new levels.
TL;DR: New bismuth oxyhalides of the type BiOI1−xBrx, form a complete solid solution series and crystallize in a layered tetragonal matlockite structure Color varies from yellow to red as x decreases from 0 75 to 0 and layer separation, c, increases from 8 45 to 9 16 A.
TL;DR: In this paper, the plasma frequencies of epitaxially grown bismuth film on BaF 2 were determined from the far-infrared reflectivity as a function of film thickness.
Abstract: The plasma frequencies (ω p ) of epitaxially grown bismuth film on BaF 2 are determined from the far-infrared reflectivity as a function of film thickness ( d ). With decreasing d , ω p increases at first and then decreases abruptly near d =100 A . This is considered as a sign of semimetal-semiconductor transition caused by the quantum size effect. The temperature dependences of ω p and its damping factor are also measured with various d . The cyclotron mass of the electron band increases with decreasing d . To explain these experimental results, the strain effects of the film due to the lattice mismatch between the film and the substrate have to be taken into account.
TL;DR: In this article, the basic properties of BiSb alloys for thermoelectric applications are discussed and a positive energy gap can be created by alloying with antimony.
TL;DR: Antimony and bismuth clusters isolated in rare-gas matrices were analyzed by Raman scattering as mentioned in this paper, and tetramers and dimers were observed in agreement with previous investigations.
Patent•
10 Dec 1985TL;DR: In this article, it was shown that Yttrium-iron magnetic domain materials having bismuth ions on dodecahedral sites are suitable for the manufacture of high-density, high-speed magnetic domain devices for operation at high and especially at very low temperatures.
Abstract: Yttrium-iron magnetic domain materials having bismuth ions on dodecahedral sites are suitable for the manufacture of high-density, high-speed magnetic domain devices for operation at high and especially at very low temperatures. In these devices magnetic domain velocity is greater than 2000 centimeters per second per oersted, and magnetic domain diameter is less than 3 micrometers. A specified operational temperature range may extend from -150 to 150 degrees C.; accordingly, such devices are particularly suitable for operation aboard satellites, e.g., in satellite communications systems.
TL;DR: The structure of Bi507I as mentioned in this paper was solved with 747 independent reflections and refined to R = 0.040 (R„= 0.034) by using double rows of iodine.
Abstract: /?-Bi507I crystallizes in space group C2/m with lattice parameters a = 18.387(4), b = 4.2497(9), c = 13.254(2) Α, β = 108.10(1)°, Ζ = 4. The structure was solved with 747 independent reflections and refined to R = 0.040 (R„ = 0.034); it consists of (Bi1 0O1 4)* + columns parallel [010] which are connected by double rows of iodine. Structural relationships to Sb 5 0 7 I exist.
Patent•
13 Dec 1985
TL;DR: In this paper, a method for preparing electrodes for use in electrochemical processes is described, where electrodes being constituted by a conductive support whereto an electrocatalytic coating is applied by galvanic deposition from a galvanic plating bath which additionally contains in dissolved or suspended form 100 to 2000 ppm of at least one additional compound of cadmium, thallium, lead, tin, arsenic, antimony, bismuth or sulphur.
Abstract: Method for preparing electrodes for use in electrochemical processes, said electrodes being constituted by a conductive support whereto an electrocatalytic coating is applied by galvanic deposition from a galvanic plating bath which additionally contains in dissolved or suspended form 100 to 2000 ppm of at least one additional compound of cadmium, thallium, lead, tin, arsenic, antimony, bismuth or sulphur. The electrodes of the invention, obtainable according to the method of the invention, when used as cathodes in membrane or diaphragm chlor-alkali cells, exhibit low hydrogen overvoltages, constant with time, and are substantially immune to poisoning by iron, mercury or other metal impurities present in the alkaline solutions.
Patent•
10 Apr 1985
TL;DR: In this article, a novel thin ribbon of semiconductor has a polycrystalline structure composed more than 50% of grains having a grain size of more than 5 μm, a thickness of 5 to 200 μm and sufficient flexibility to be windable on a pipe having a diameter of 34 mm, and malleability.
Abstract: A novel thin ribbon of semiconductor has a polycrystalline structure composed more than 50% of grains having a grain size of more than 5 μm, a thickness of 5 to 200 μm, a sufficient flexibility to be windable on a pipe having a diameter of 34 mm, and malleability. The semiconductor is composed of p-type, i-type or n-type semiconductor material, and may be a two-layer composite formed of at least two elements so as to form a p-n type junction. The composition of the semiconductor material consists of pure silicon or silicon with an additional impurity element for improving the properties of the semiconductor, the additional impurity element being selected from the group consisting of hydrogen, phosphorus, sulfur, oxygen, boron, arsenic, tellurium, tin, selenium, aluminum, gallium, indium, chromium, silver, iron and bismuth. A method of manufacturing a thin ribbon of a two-layer composite of semiconductor material is also disclosed. The flexible thin ribbon of semiconductor is available for use as/or in a semiconductor electronic device.
TL;DR: The data suggest that some gastrointestinal mucosal uptake of bismuth occurs in colloidal bismUTH subcitrate treated rats, and a brush border membrane and cytosolic localisation are seen in duodenal enterocytes.
Abstract: Despite the topical action of colloidal bismuth subcitrate in promoting the healing of peptic ulcers, slight absorption of bismuth from the gastrointestinal tract has been reported in colloidal bismuth subcitrate-treated animals and man. The uptake and subcellular distribution of bismuth by the gastrointestinal tract of rats after 24 hours of colloidal bismuth subcitrate administration was studied. Mucosal uptake of bismuth (mean +/- SEM nmol/g protein) by gastric fundus (8.85 +/- 1.0) and antrum (7.23 +/- 1.50) was similar, but was significantly less than duodenum (19.2 +/- 3.7, p less than 0.05), jejunum (26.9 +/- 2.4, p less than 0.001) or ileum (22.4 +/- 2.2, p less than 0.001). Bismuth concentrations in antral and duodenal mucosae fell progressively over 72 hours to approximately 10% of initial concentrations (p less than 0.02). Subcellular fractionation studies of colloidal bismuth subcitrate treated duodenal enterocytes showed a brush border membrane and cytosolic localisation. These data suggest that some gastrointestinal mucosal uptake of bismuth occurs in colloidal bismuth subcitrate treated rats.
TL;DR: It is shown that insertion losses would be decreased by increasing the bismuth substitution x, and the fiber-embedded micro-Faraday rotator can be used in a fiber isolator not only for 1.3 μm but also for 0.8-μm wavelength regions.
Abstract: An infrared Faraday rotator embedded in a fiber is proposed and fabricated using Gd3−xBixFe5O12 single crystals; the specific bismuth substitution x was ∼0.9 in our experiments. Insertion losses for multimode and single-mode fibers are 2.9 and 4.3 dB at the 1.29-μm wavelength, respectively, and 4.3 and 6.7 dB at the 0.78-μm wavelength, respectively. It is shown that insertion losses would be decreased by increasing the bismuth substitution x. The fiber-embedded micro-Faraday rotator can be used in a fiber isolator not only for 1.3 μm but also for 0.8-μm wavelength regions.