Showing papers on "Bismuth published in 1976"
TL;DR: In this paper, a review of the progress achieved in the understanding of the origin of the large bismuth induced magnetooptic effects in iron garnets is made, and optical efficiencies are determined by the ratio of Faraday rotation (θ) to optical absorption (α).
Abstract: Using the results of the phenomenological and microscopic description of magnetooptically active transitions presented in the beginning of the article, a review is made of the progress achieved in the understanding of the origin of the large bismuth induced magnetooptic effects in iron garnets. For applications involving the Faraday configuration, optical efficiencies are determined by the ratio of Faraday rotation (θ) to optical absorption (α). The dependence of θ/α on such variables as bismuth concentration, 4\piM_{s} and impurity ions is discussed with its spectral behavior. Finally, the behavior of bismuth substituted iron garnets in devices previously devised using unsubstituted iron garnets is discussed, in conjunction with devices which have only become feasible as a consequence of improvements in the optical properties of such iron garnets.
190 citations
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TL;DR: In this article, a review of the electronic properties of pure bismuth is given, and the validity of the Cohen model as a first approximation to the electron spectrum is established, and deviations from this model are described.
Abstract: A review of the electronic properties of pure bismuth is given. Theoretical ideas on the band structure of bismuth and the dispersion relation for electrons near the bottom of the conduction band are briefly outlined. The experiments considered are those which give the most precise information on the Fermi surface (quantum effects in conductivity, cyclotron resonance, size effects, magnetoplasma waves, etc.) and on the electron energy spectrum near the bottom of the conduction band (studies in the quantum limit, infra-red magneto-reflection). The validity of the Cohen model as a first approximation to the electron spectrum in bismuth is established, and deviations from this model are described. Experiments are proposed which may give additional information on electrons in bismuth.
170 citations
TL;DR: In this article, a scheme of analysis for the determination of arsenic, antimony, bismuth, lead, selenium, tellurium and tin in steel by evolution of their volatile hydrides and subsequent atomic absorption spectrometry in an argon-hydrogen-entrained air flame was presented.
130 citations
TL;DR: In this paper, the authors reported preliminary results from their experiment on the 648 nm J = 3/2 J = 5/2 transition in bismuth and found that the optical rotation, if it exists, must be somewhat smaller than had been expected.
Abstract: Bouchiat and Bouchiat pointed out1 soon after the discovery of weak neutral currents2 that their existence might lead to parity non-conserving (PNC) effects of observable magnitude in atoms. One of the most promising possibilities3 is to look for optical rotation close to an allowed M1 absorption line in a heavy element. We report here preliminary results from our experiment4 on the 648 nm J = 3/2 J = 5/2 transition in bismuth. We find that the optical rotation, if it exists, must be somewhat smaller than had been expected.
80 citations
TL;DR: In this article, the authors found that Bi 3 (FeO 4 )(MoO 4 ), a highly active and selective catalyst for the oxidation of 1-butene to butadiene over the temperature range of 350-450 °C.
70 citations
TL;DR: In this article, the surface structure of bismuth molybdate catalysts after outgassing, after interaction with hydrogen and after interacting with propylene-oxygen mixture was studied.
69 citations
TL;DR: The new, layered bismuth titanates, Bi7Ti4NbO21 and Bi6Ti3WO18, were synthesized by heating mixtures of the constituent oxides at 1100 °C in air, and were analyzed by X-ray powder diffraction as mentioned in this paper.
Abstract: The new, layered bismuth titanates, Bi7Ti4NbO21 and Bi6Ti3WO18, were synthesized by heating mixtures of the constituent oxides at 1100 °C in air, and were analyzed by X-ray powder diffraction. Bi7Ti4NbO21 has an orthorhombic cell with a = 5.44, b = 5.40 and c = 29.05 A, and it is thought that the structure is built up by regular intergrowth of Bi4Ti3O12 and Bi3TiNbO9 layers along the c-axis. Bi6Ti3WO18 has an orthorhombic cell with a = 5.38, b = 5.40 and c = 24.96 A, which is consistent with that of Bi3TiNbO9 reported by Wolfe et al., and with which it is thought to be iso-structural.
69 citations
TL;DR: In this article, the fracture surfaces of an alloy of copper containing 60 p.p.m. of bismuth have been analyzed by Auger electron spectroscopy and the results show marked anisotropy in the segregation of bistuth to the intergranular fracture surface.
Abstract: The fracture surfaces of an alloy of copper containing 60 p.p.m. of bismuth have been analysed by Auger electron spectroscopy. Alloys annealed in the temperature range 400° to 700°C before fracture all show marked anisotropy in the segregation of bismuth to the intergranular fracture surface. This is in marked contrast to the results obtained by Seah and Hondros (1973) for sulphur and tin segregation in iron. Possible reasons for this contrasting behaviour are discussed briefly.
68 citations
TL;DR: In this paper, the early stages in the formation of a continuous anodic layer of bismuth oxide on a solid Bismuth electrode, in the pH range 5-14, were studied.
60 citations
TL;DR: The formation of the adsorbed layer, however, is preceded by bulk deposition as discussed by the authors, and with the ionization of the bulk metal the formation of a strongly adorbed species is begun.
55 citations
TL;DR: The specific adsorption of Cl− ions at the bismuth-ethanol interface has been studied both in the solutions of mixed electrolytes with constant ionic strength and in the binary LiCl solutions by the method of measuring the potential dependence of differential capacity as mentioned in this paper.
TL;DR: In this paper, an electron microscope study of copper-bismuth alloys has shown a high incidence of faceting of the grain boundaries, suggesting the bismuth has a large effect on the low energy configurations of the boundary plane.
Abstract: An electron microscope study of copper-bismuth alloys has shown a high incidence of faceting of the grain boundaries. This is not observed in pure copper, suggesting the bismuth has a large effect on the low energy configurations of the boundary plane.
TL;DR: In this article, 15 new iodobis(dialkyldithiocarbamate) complexes of arsenic, antimony and bismuth have been prepared by reacting the corresponding tris(dilithithiamates) with iodine, and a possible mechanism of the reaction has been proposed.
TL;DR: In this paper, the reflection spectra of BiI s single crystals were measured between 1.5 and 5.5 eV at 6, 77 and 286 K, and the intrinsic absorption coefficient and the real and imaginary parts of the dielectric constants were calculated.
Abstract: The reflection spectra of BiI s single crystals were measured between 1.5 and 5.5 eV at 6, 77 and 286 K. A Kramers-Kronig dispersion analysis of the data was made, and the intrinsic absorption coefficient and the real and imaginary parts of the dielectric constants were calculated. The large peak at 2.0 eV is ascribed to direct excitonic transition near the fundamental absorption edge. The main features observed in the absorption spectra are discussed in terms of two proposed models for anionic and cationic excitons in heavy metal halides. Measurements have also been made on the ordinary refractive index near the absorption edge. The data are well described by a two-oscillator model.
TL;DR: In this paper, it was shown that bismuth colloids of colloidal particles give the characteristic optical absorption band in the uv region (up to 275 nm), which can be attributed to the thermionic emission of electrons from colloid particles and give characteristic conduction-electron spin-resonance signals (18 G in KBr).
Abstract: Bismuth enters into the alkali halide lattice in its trivalent and/or divalent state if it is introduced by diffusion of bismuth vapors at appropriate temperatures. In its trivalent state its ground state is $^{1}S_{0}$ and transitions from this level to the $^{3}P_{1}$, $^{3}P_{2}$, and $^{1}P_{1}$ states are the well known $A$, $B$, $C$ bands of the $n{s}^{2}$ configuration. Such bands are observed in NaCl, KCl, KBr, and RbCl crystals doped with bismuth. In its divalent state bismuth has one intense band at \ensuremath{\sim} 390 nm. On radiation damage or additive coloration it is possible to reduce the valence state, and by controlled experiments it has thus been possible to introduce and study the properties of ${\mathrm{Bi}}^{+++}$, ${\mathrm{Bi}}^{++}$, ${\mathrm{Bi}}^{+}$, ${\mathrm{Bi}}^{0}$, and even colloids of atomic bismuth in these crystals. When the colloids of bismuth are formed, the centers give the characteristic optical absorption band in the uv region (\ensuremath{\sim} 275 nm), give enhanced conductivity which can be attributed to thermionic emission of electrons from bismuth colloidal particles, and give characteristic conduction-electron spin-resonance signals (18 G in KBr). These features persist till the melting point of the crystal and their intensity is a function of concentration. Electron microscopic studies lend support to this interpretation.
TL;DR: In this paper, the results of activity measurements of liquid copper binary alloys containing lead, thallium, bismuth, antimony, zinc, cadmium, tellurium, selenium, arsenic, indium, silver and tin are summarized.
TL;DR: The direct determination of bismuth in urine by means of hydride generation has been investigated, and it is shown that there is severe suppression and poor recovery.
Abstract: Bismuth is determined in blood and urine by means of atomic-absorption spectrophotometry following generation of bismuth hydride from a wet-oxidised sample. Recoveries are shown to be satisfactory, and the detection limit using analytical-reagent grade reagents is less than 0.01 µg ml–1.The direct determination of bismuth in urine by means of hydride generation has been investigated, and it is shown that there is severe suppression and poor recovery.
TL;DR: In this paper, the determination of bismuth at the 0-1 p.p.m. level in nickel-base alloys after dissolution of the alloy followed by generation of Bismuth hydride and its subsequent measurement by atomic-absorption spectrophotometry is discussed.
Abstract: A requirement has arisen in the aero-engine industry for a method that is capable of determining trace amounts of bismuth in complex nickel-base alloys. This paper deals with the determination of bismuth at the 0–1 p.p.m. level in nickel-base alloys after dissolution of the alloy followed by generation of bismuth hydride and its subsequent measurement by atomic-absorption spectrophotometry. Interference effects, due to the complex matrix, have been overcome and a procedure has been developed that is rapid and sensitive at these very low levels. The method is applicable to a wide range of nickel-base alloys commonly used in the aero-engine industry.
TL;DR: In this article, the magnetic-field-induced surface-state resonance of bismuth was measured for the surface parallel to the binary plane and it was found that the spectra near the heavy-mass direction can neither be interpreted with the band model by Lax nor with that by Cohen.
Abstract: The magnetic-field-induced surface-state resonance of bismuth was measured for the surface parallel to the binary plane. From the observed resonance signal, we could obtain information on the Fermi surface of electrons along the equator parallel to the binary plane. It was found that the spectra near the heavy-mass direction can neither be interpreted with the band model by Lax nor with that by Cohen. They were explained satisfactorily with a "hybrid" model in which both the two-band coupling and the remote-band effect are taken into account in the heavy-mass direction.
Patent•
01 Jun 1976TL;DR: In this paper, a technique for melting X-ray absorbing glass compositions by a process wherein molten glass is floated or supported on a bath of molten tin is described, where the glass compositions are free of the oxides of lead, arsenic, antimony, bismuth, cadmium and other readily reducible oxides to prevent discoloration of the glass upon contact with molten metal.
Abstract: Disclosed is a technique for melting X-ray absorbing glass compositions by a process wherein molten glass is floated or supported on a bath of molten tin. The X-ray absorbing glass compositions are free of the oxides of lead, arsenic, antimony, bismuth, cadmium, and other readily reducible oxides to prevent discoloration of the glass upon contact with molten metal.
TL;DR: This paper describes a relatively simple and rapid analytical procedure capable to carry out systematic screening for 10 heavy metals, namely mercury, bismuth, antimony, copper, lead, tin, thallium, indium, cadmium and zinc.
Abstract: This paper describes a relatively simple and rapid analytical procedure capable to carry out systematic screening for 10 heavy metals, namely mercury, bismuth, antimony, copper, lead, tin, thallium, indium, cadmium and zinc.
Patent•
14 Jun 1976TL;DR: A low-pressure mercury vapor discharge lamp with two thermally emitting electrodes as well as an amalgam of bismuth, indium and mercury is characterized in this article, in which the ratio of atoms of Bismuth to atoms of indium is between 0.4:0.6 and 0.7: 0.3.
Abstract: A low-pressure mercury vapor discharge lamp having a discharge space provided with two thermally emitting electrodes as well as an amalgam of bismuth, indium and mercury, characterized in that the ratio of atoms of bismuth to atoms of indium is between 0.4:0.6 and 0.7:0.3 and the ratio of atoms of mercury to the sum of the atoms of bismuth and indium is between 0.01:0.99 and 0.15:0.85.
Patent•
31 Mar 1976
TL;DR: A process for the adsorptive removal of one or more impurity elements, selected from the group which consists of: arsenic, antimony and bismuth, from an aqueous solution containing the same in which the solution is contacted with a water-insoluble or low-solubility salt of a phosphoric acid or aosphate ester on a porous substrate is described in this article.
Abstract: A process for the adsorptive removal of one or more impurity elements, selected from the group which consists of: arsenic, antimony and bismuth, from an aqueous solution containing same in which the solution is contacted with a water-insoluble or low-solubility salt of phosphoric acid or a phosphoric acid ester (phosphate ester) on a porous substrate.
TL;DR: In this paper, the nuclear quadrupole resonance of 75As and 209Bi have been observed in metallic arsenic and bismuth respectively, in good agreement with the value deduced from low-temperature specific heat measurements.
TL;DR: In this paper, the authors measured the resistivity of thin Bi films on silicon and compared the result of a numerical calculation based on the equation which was proposed by Mayadas and Shatzkes.
TL;DR: In this article, the elastic stiffness constant tensor components of single crystals of bismuth and its alloys (3 at.%Sb, 5 at.%.%.%.
Abstract: The elastic stiffness constant tensor components of single crystals of bismuth and its alloys (3 at.%Sb, 5 at.%Sb, 7 at.%Sb and 10 at.%Sb) with antimony have been obtained between 4.2K and room temperature from measurements of ultrasonic wave velocities made by the pulse echo overlap technique. In contradiction with previous work on polycrystalline alloys the ultrasonic velocities are found to increase smoothly with antimony composition. The electronic contribution to the elastic constants is negligibly small. The temperature dependences of the elastic constants, which are remarkably similar for bismuth and the alloys, have been fitted by an anharmonic oscillator model.
TL;DR: In this article, low-temperature transport measurements were performed for pure bismuth and for a modified version with equal amounts of tin and tellurium, and it was shown that the compensated sample acts as a compensated semimetal with pronounced impurity scattering.
Abstract: Low-temperature transport measurements are reported for pure bismuth and for bismuth doped with equal amounts of tin and tellurium. Electrical resistivity and thermoelectric power data indicate that the compensated sample acts as a compensated semimetal with pronounced impurity scattering. If a rigid-band model and the validity of Matthiessen's rule are assumed, then it appears that the tin and tellurium act as a kind of neutral complex yielding a temperature independent scattering mechanism for electrons and holes.
TL;DR: In this article, the arsenic containing analogue of triptycene, 5,10- o -benzenoarsanthrene A (E=As) was isolated some time ago, and the related derivatives of antimony and bismuth are unknown.
TL;DR: The machanisms of thermal decompositions have been studied of the following bismuth(III) salts: benzoate, salicylate, subbenzoate and subsalicylates.
TL;DR: The electroreduction of a bismuth anodic oxide film is shown to involve electron migration in the film with reaction at the film-solution interface in this paper, where the electron migration was shown to be caused by electron migration.