Showing papers on "Bismuth published in 2005"
TL;DR: In this paper, the development, behavior, scope and prospects of bismuth electrodes for stripping-based electrochemical measurements of trace metals are reviewed, with applications ranging from continuous remote sensing to single-use measurements.
Abstract: For many years mercury electrodes were the transducer of choice in stripping voltammetry of trace metals owing to their high sensitivity, reproducibility, and renewability. However, because of the toxicity of mercury, alternative (‘environmentally friendly’) electrode materials are highly desired for both centralized and field applications. Recently introduced bismuth electrodes offer a very attractive alternative to commonly used mercury electrodes. Such electrodes display well-defined, undistorted and highly reproducible response, favorable resolution of neighboring peaks, high hydrogen evolution, with good signal-to-background characteristics comparable to those of common mercury electrodes. The attractive stripping behavior of bismuth electrodes reflects the ability of bismuth to form ‘fused’ multicomponent alloys with heavy metals. Bismuth stripping electrodes thus hold great promise for decentralized metal testing, with applications ranging from continuous remote sensing to single-use measurements. Fundamental studies aimed at understanding the behavior of bismuth film electrodes should lead to rational preparation and operation of reliable alternative (‘non–mercury’) stripping electrodes that would have a major impact upon electroanalysis of trace metals. This article reviews the development, behavior, scope and prospects of bismuth electrodes for stripping-based electrochemical measurements of trace metals.
514 citations
TL;DR: A new liquid metal ion gun filled with bismuth has been fitted to a time-of-flight—secondary ion mass spectrometer (TOF-SIMS) and the results show a great improvement of the imaging capabilities in terms of accessible mass range and useful lateral resolution.
326 citations
TL;DR: In this paper, a new fiber laser based on a bismuth-doped aluminosilicate glass fiber is proposed and fabricated and obtained in the spectral region between 1150 and 1300 nm.
Abstract: A new fibre laser based on a bismuth-doped aluminosilicate glass fibre is proposed and fabricated. CW lasing is obtained in the spectral region between 1150 and 1300 nm. The fibres are fabricated by the method of modified chemical vapour deposition.
315 citations
TL;DR: In this paper, the authors predict the occurrence of large ferroelectric polarization and piezoelectricity in the hypothetical perovskite-structure oxides, bismuth aluminate (BiAlO 3 ) and BiGaO 3, using density functional theory within the local density approximation.
Abstract: We predict the occurrence of large ferroelectric polarization and piezoelectricity in the hypothetical perovskite-structure oxides, bismuth aluminate (BiAlO 3 ) and bismuth gallate (BiGaO 3 ), using density functional theory within the local density approximation. We show that BiGaO 3 will have a similar structure to PbTiO 3 , although with much stronger tetragonal distortion and therefore improved ferroelectric properties. Likewise, BiAlO 3 shares structural characteristics with antiferrodistortive PbZrO 3 , but it is also a ferroelectric with large polarization. Therefore, we propose the Bi(Al,Ga)O 3 system as a replacement for the widely used piezoelectric material, Pb(Zr,Ti)O 3 (PZT), that will avoid the environmental toxicity problems of lead-based compounds. Finally, we show that, in both BiAlO 3 and BiGaO 3 , the large distortions from the prototypical cubic structure are driven by the stereochemical activity of the Bi lone pair.
314 citations
TL;DR: In this article, a low-temperature synthesis route of preparing bismuth ferrite nanopowders through soft chemical route using nitrates of Bismuth and Iron is described.
Abstract: The present research describes a simple low-temperature synthesis route of preparing bismuth ferrite nanopowders through soft chemical route using nitrates of Bismuth and Iron. Tartaric acid is used as a template material and nitric acid as an oxidizing agent. The synthesized powders are characterized by X-ray diffractometry, thermogravimetry and differential thermal analysis, infrared spectroscopy, and scanning electron microscopy. The particle size of the powder lies between 3 and 16 nm. In the process, phase pure bismuth ferrite can be obtained at a temperature as low as 400°C, in contrast to 550°C for coprecipitation route. On the other hand, we find that, like solid state reaction route, Pechini's autocombustion method of synthesis generates a lot of impurity phases along with bismuth ferrite.
309 citations
TL;DR: In this paper, a polycrystalline BiFeO3 thin film was fabricated on (111)Pt∕Ti∕SiO2 ∕Si substrates via Bi-acetate-and Fe-acetylacetonate-based chemical solution deposition and spin-coating techniques.
Abstract: Polycrystalline BiFeO3 thin films were fabricated on (111)Pt∕Ti∕SiO2∕Si substrates via Bi-acetate- and Fe-acetylacetonate-based chemical solution deposition and spin-coating techniques. The processing parameters were optimized in order to obtain films with high resistivity. The optical properties (refractive indices and extinction coefficients) were measured by means of ellipsometry (HeNe laser, λ=632.8A). Microstructure characterization was made by means of atomic force microscopy, grazing incidence x-ray diffractometry (XRD), and texture analysis. Additionally, powders prepared from a stoichiometric precursor were investigated by means of thermogravimetric and differential thermal analyses and XRD. It is demonstrated that the formation of perovskite-type BiFeO3 is accompanied by the appearance of bismuth oxide at low temperatures which then transforms into Bi36Fe2O57. For the films it was found that annealing in oxygen leads to higher indices of refraction, lower roughness, and smaller grain size. Compl...
250 citations
TL;DR: Near-infrared broadband emission from bismuth-tantalum-codoped germanium oxide glasses was observed at room temperature when the glasses were pumped by an 808 nm laser diode.
Abstract: Near-infrared broadband emission from bismuth-tantalum-codoped germanium oxide glasses was observed at room temperature when the glasses were pumped by an 808 nm laser diode. The emission band covered the 0, E, S, C, and L bands (1260-1625 nm), with a maximum peak at similar to 1310 nm, a FWHM broader than 400 nm, and a lifetime longer than 200 lis. The observed broadband luminescence was attributed to bismuth clusters in the glasses. Bismuth-tantalum-codoped germanium oxide glass might be promising as amplification media for broadly tunable lasers and wideband amplifiers in optical communications. (c) 2005 Optical Society of America.
213 citations
TL;DR: It is shown that the combination of unusual features specific to semimetals gives rise to a unique ordering and spacing of three characteristic energy scales, which not only is specific toSemimetals but which concomitantly provides a wide window for the observation of apparent field-induced metal-insulator behavior.
Abstract: When high quality bismuth or graphite crystals are placed in a magnetic field directed along the c axis (trigonal axis for bismuth) and the temperature is lowered, the resistance increases as it does in an insulator but then saturates. We show that the combination of unusual features specific to semimetals, i.e., low carrier density, small effective mass, high purity, and an equal number of electrons and holes (compensation), gives rise to a unique ordering and spacing of three characteristic energy scales, which not only is specific to semimetals but which concomitantly provides a wide window for the observation of apparent field-induced metal-insulator behavior. Using magnetotransport and Hall measurements, the details of this unusual behavior are captured with a conventional multiband model, thus confirming the occupation by semimetals of a unique niche between conventional metals and semiconductors.
197 citations
TL;DR: The composition and morphologies of the bismuth oxyhalide crystalline nanobelts could be controlled by adjusting some growth parameters, including reaction pH, time, and temperature.
Abstract: Ternary bismuth oxyhalide crystalline nanobelts (such as Bi 2 4 - O 3 1 Br 1 0 , Bi 3 O 4 Br, Bi 1 2 O 1 7 Br 2 , BiOCl. and Bi 2 4 O 3 1 Cl 1 0 ) and nanotubes (such as Bi 2 4 O 3 1 Br 1 0 ) have been synthesized by using convenient hydrothermal methods. The composition and morphologies of the bismuth oxyhalides could be controlled by adjusting some growth parameters, including reaction pH, time, and temperature. All the nanostructures were characterized by using various methods including X-ray diffraction, transmission electron microscopy, high-resolution TEM, electron diffraction, and energy-dispersive X-ray analysis. The possible reaction mechanism and growth of the crystals are discussed based on the experimental results.
196 citations
TL;DR: In this paper, the structures, phase transformations, and dielectric properties of pyrochlore ceramics containing bismuth were studied, and the relation between the orthorhombic and cubic pyroglores in the Bi2O3-ZnO-Nb2O5 (BZN) system was investigated.
Abstract: The structures, phase transformations, and dielectric properties of pyrochlore ceramics containing bismuth were studied. The relation between the orthorhombic and cubic pyrochlores in the Bi2O3-ZnO-Nb2O5 (BZN) system has been investigated. The effect of bismuth in distorted cubic pyrochlore structures is discussed. BZN compositions with pyrochlore structures have excellent dielectric properties, very low dielectric loss, and high dielectric constants with stable frequency and temperature dependence.
188 citations
TL;DR: The sensitive catalytic voltammetric method was applied with satisfactory results to the determination of iron in certified reference river water samples, obtained without any preconcentration procedure.
Abstract: A sensitive catalytic voltammetric method for determining trace iron at a bismuth film electrode (BiFE) is described. The method is based on the cathodic reduction of the Fe(III)–triethanolamine (TEA) complex to Fe(II). It has been proved that the addition of KBrO3 causes rapid oxidation of Fe(II) and TEA, and therefore results in a large increase in the analytical signal from Fe(III) when TEA is placed in alkaline solution. When TEA was present in the solution, operating the BiFE under optimized conditions yielded a stable catalytic voltammetric response for iron, with high sensitivity (0.88 μA μM−1), good precision (RSD=3.9%) and a low detection limit (7.7×10−9 M), obtained without any preconcentration procedure. Possible interferences from the coexisting ions and surface-active substances were investigated. Finally, the method was applied with satisfactory results to the determination of iron in certified reference river water samples.
TL;DR: In this article, the authors reported the synthesis of magnetoelectric bismuth ferrite by a ferrioxalate precursor method using X-ray diffractometry, thermogravimetry and differential thermal analysis, Fourier transformation infrared spectroscopy and scanning electron microscopy.
TL;DR: In this article, a simple method to fabricate nanowires with radii as small as 90nm from compound-glass fibres is described, and low transmission losses at 1.55 µm have been achieved in nanowsires fabricated from lead-silicate and bismuth silicate optical fibres.
Abstract: A simple method to fabricate nanowires with radii as small as 90nm from compound-glass fibres is described. Low transmission losses at 1.55µm have been achieved in nanowires fabricated from lead-silicate and bismuth silicate optical fibres.
TL;DR: This is the first example of highly enantioselective reactions using a chiral bismuth catalyst in aqueous media and adds Bi(OTf)(3)-1 complex as a "water-compatible Lewis acid".
TL;DR: The optical properties of bismuth oxide films prepared by pulsed laser deposition (PLD), absorption in the photon energy range 2.50-4.30 eV and optical functions (n, k, ǫ1, and Ãǫ2) in the domain 3.20-6.50 eV, have been investigated in this article.
Patent•
22 Dec 2005TL;DR: In this article, a process for producing bismuth-containing oxide thin films by atomic layer deposition is described, which can be used as ferroelectric or dielectric materials in integrated circuits and as superconductor materials.
Abstract: Processes are provided for producing bismuth-containing oxide thin films by atomic layer deposition. In preferred embodiments an organic bismuth compound having at least one monodentate alkoxide ligand is used as a bismuth source material. Bismuth-containing oxide thin films can be used, for example, as ferroelectric or dielectric materials in integrated circuits and as superconductor materials.
TL;DR: In this article, the spectroscopic properties of GeO2:Bi,Al glasses strongly depend on the glass compositions and the pumping sources and the broadband luminescence covering 1.2-1.6 mu m was observed from bismuth and aluminum co-doped germanium oxide glasses pumped by 808 nm laser at room temperature.
Abstract: The broadband luminescence covering 1.2-1.6 mu m was observed from bismuth and aluminum co-doped germanium oxide glasses pumped by 808 nm laser at room temperature. The spectroscopic properties of GeO2:Bi,Al glasses strongly depend on the glass compositions and the pumping sources. To a certain extent, the Al3+ ions play as dispersing reagent for the infrared-emission centers in the GeO2:Bi,Al glasses. The broad infrared luminescence with a full width at half maximum larger than 200 nm and a lifetime longer than 200 mu s possesses these glasses with the potential applications in broadly tunable laser sources and ultra-broadband fiber amplifiers in optical communication field. (c) 2005 Elsevier B.V. All rights reserved.
TL;DR: In this paper, a study on the preparation and characterisation of ex situ formed bismuth film microelectrodes (BiFMEs) is presented, focusing in particular on their stable and reliable stripping electroanalytical performance.
TL;DR: In this article, the thermoelectric properties (Seebeck coefficient, electrical resistivity, and carrier concentration) of coevaporated bismuth-tellurium and antimony tellurium films were measured under various deposition conditions (controlled evaporation rates of individual species, substrate temperature, and substrate material).
Abstract: Coevaporated bismuth-tellurium and antimony-tellurium films were fabricated under various deposition conditions (controlled evaporation rates of individual species, substrate temperature, and substrate material), and their thermoelectric (TE) properties (Seebeck coefficient, electrical resistivity, and carrier concentration) were measured in search of optimal TE performance. The tellurium atomic concentration was varied from 48% to 74%, the substrate temperature ranged from 130 to 300 °C, and glass, mica, magnesium oxide, and sapphire substrates were used. The chemical composition and crystal structure of the films were recorded (using microprobe and x-ray diffractometer, respectively), analyzed, and compared with available standard Bi2Te3 and Sb2Te3 single-crystal samples. High-performance TE films had tellurium atomic concentration around 60% and were deposited at a substrate temperature between 260 and 270 °C.
TL;DR: In this paper, the X-ray diffraction patterns of Bi 2 O 3 thin films have been analyzed for structural, surface morphological, optical and electrical properties and it was found that after annealing a non-stoichiometric phase, Bi 2 2 O 2.33, was removed and phase pure monoclinic Bi O 3 was obtained.
TL;DR: Bismuth tungsten oxide (Bi2WO6) is an m = 1 Aurivillius phase and some of its doped compounds show moderately high oxygen ion conductivity as discussed by the authors.
Abstract: Bismuth tungsten oxide (Bi2WO6) is an m = 1 Aurivillius phase and some of its doped compounds show moderately high oxygen ion conductivity. These materials are structurally related to the more diso...
TL;DR: In this paper, the effects of minor additions of Cu, Bi, and In on microstructure, melting temperature, and tensile properties of Sn-Ag-based lead-free solders were investigated.
Abstract: Effects of minor additions of Cu, Bi, and In on microstructure, melting temperature, and tensile properties of Sn-Ag-based lead-free solders were investigated. It was found that the intermetallic compounds (IMCs) Ag2In and Cu6Sn5 are formed in In- and Cu-containing solders, respectively. At low concentration, Bi dissolved in the Sn matrix and tended to precipitate pure Bi particles at the solubility limit of 4 wt pct Bi. The formation of large Ag3Sn precipitates from the solder matrix was suppressed when alloying bismuth into the Sn-Ag alloy. The Bi addition resulted in a significant linear increase of the ultimate tensile strength (UTS) of solders, which is attributed to a solid-solution hardening mechanism. Solder strengthening due to In and Cu is less pronounced and attributed to a dispersion strengthening mechanism. The additions of Cu, Bi, and In all depressed the melting temperatures of Sn-Ag-based solders; however, In is the most effective one.
TL;DR: In this article, a new approach for a cloud point extraction electrothermal atomic absorption spectrometric method was used for determining bismuth in tap water and biological samples (urine and hair).
TL;DR: Bismuth film electrodes, formed by electrochemical deposition on carbon film resistor electrode substrates at constant applied potential, by potential cycling or at constant current have been investigated for the first time as discussed by the authors.
Abstract: Bismuth film electrodes, formed by electrochemical deposition on carbon film resistor electrode substrates at constant applied potential, by potential cycling or at constant applied current have been investigated for the first time The electrochemical behaviour of the films was characterised by cyclic voltammetry and electrochemical impedance spectroscopy and they were applied to the determination of Zn, Cd, and Pb by square-wave anodic stripping voltammetry The highest sensitivities coupled with nanomolar detection limits were achieved at bismuth films formed at constant potential; however, in situ deposited bismuth films exhibited better reproducibility Future application as small, short-term-use sensors is indicated
01 Apr 2005
TL;DR: In this article, Bismuth (Bi) nanocrystals are used for solution-liquid-solid (SLS) synthesis of crystalline InAs, GaP, GaAs, and InP nanowires at temperatures between 300 and 340 °C in trioctylphosphine (TOP), TOPO, and trioctylamine (TOA).
Abstract: Bismuth (Bi) nanocrystals are used for solution−liquid−solid (SLS) synthesis of crystalline InAs, GaP, GaAs, and InP nanowires at temperatures between 300 and 340 °C in trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO), and trioctylamine (TOA). Bi nanocrystals are observed at the nanowire tips, confirming their role as crystallization seeds. The nanowires are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD).
TL;DR: The change in permittivity of bismuth zinc niobate (BZN) films with the cubic pyrochlore structure under an applied electric field was measured as a function of temperature.
Abstract: The change in permittivity of bismuth zinc niobate (BZN) films with the cubic pyrochlore structure under an applied electric field was measured as a function of temperature. Dielectric measurements were performed using parallel-plate capacitor structures with Pt electrodes on sapphire substrates. The electric field tunability of the permittivity was weakly temperature dependent and increased with decreasing temperature up to the onset of dielectric relaxation. At temperatures below the onset of the dielectric relaxation (similar to150 K at 1 MHz), larger electric fields were required to achieve the highest tunabilities. A simple model of hopping, noninteracting dipoles was not suited to describe. the dielectric tunability of BZN thin films. A better description of the experimentally observed behavior at temperatures above the onset of the dielectric relaxation was obtained using a simple random-field model with hopping dipoles in a uniform distribution of random fields. (C) 2005 American Institute of Physics.
TL;DR: In this paper, the electrochemical properties of bismuth and germanium irreversibly adsorbed on platinum electrodes have been used to screen the surface domains of polycrystalline electrodes.
TL;DR: In this paper, the presence of bismuth surfactant was found to increase the nitrogen incorporation in the dilute nitride GaN x As 1−x by as much as 60% during growth by molecular beam epitaxy.
Metz1
TL;DR: In this article, the processes associated with the electrodeposition of bismuth antimony telluride thermoelectric films, were reported along with an analysis of the composition and crystallinity of the resulting films.