Narrow Results

Bismuth (Bi) content of electrum from Mongolian artisanal/small-scale mining sites was determined by micro-PIXE at CSIRO. This is to provide artisanal/small-scale miners information on the valuable trace element in electrum which they recover from quartz veins. The analysis was done using a 3 MeV micro-beam (30 micrometer in diameter) with an aluminum filter of 125 micrometer thickness. The result showed that electrum grains from the study area contains Bi with a range from 0 to 2,530 ppm.

We have examined tin-polymetallic ore, a complex mixture of cassiterite (SnO₂) and sulfides, by micro-PIXE. Tin-polymetallic ore is one of the major sources of technologically important “rare metals”, especially of indium and bismuth, usually as trace elements. In addition to such rare metals, silver is another important trace component in the ore. But the trace elemental distribution of tin-polymetallic deposit has not well been described due to the small size of constituent minerals, complex ore texture, and lack of analytical method to detect trace elements in a small area. PIXE with a proton microbeam could be an effective tool to solve this problem by delineating the distribution of these trace elements among carrier minerals with the required sensitivity. Thus we have applied PIXE with the CSIRO’s proton microprobe to a tin-polymetallic ore from Canada. The result showed that micro-PIXE is an essential tool to study trace element distribution in such a complex ore.

We intend to study the half-lives of Bismuth isotopes via the alpha decay process. To go through the problem, we consider a potential model in which an angle-dependence is considered. Our results reveal that taking into account the multipole approximations for both parent and daughter nuclei will improve the results.

In this paper, the alpha decay process is investigated through the theoretical approaches for spherical Bismuth (Bi) isotopes in the range 187 $\le$ A $\le$ 214. The results are compared with the experimental data for isotopes of Bi with the modified Coulomb and proximity potential model (MCPPM). We analyze the systematics of alpha decay half-life (HL) of Bi isotopes versus the decay energy and the total $\alpha$-kinetic energy. The results and their systematics are compared with the available experimental data and with those data obtained from empirical models as the Viola-Seaborg (VS) formula, Royer (R) and the two versions of modified Brown (mB) empirical formulas. The computed half-lives (HLs) are compared with the experimental data and also with the existing empirical estimates and are found in good agreement.

We report the reaction dynamics of the Bi-line structure (BLS) with copper-phthalocyanine (CuPc)molecules as well as hydrogen and Ag atoms on Si(100) surfaces observed by scanning tunneling microscopy. Co-adsorption of hydrogen and Ag on the Si(100) surface with BLSs brought about agglomeration of Ag atoms on the Si terrace. When CuPc molecules were deposited on the Si(100) surface with BLSs at room temperature, domains with c(4 × 4) periodicity appeared in the terraces near the BLS. When the surface was annealed at 200°C–400°C, the area of the c(4 × 4) domain was increased. The CuPc molecules, adsorbed on BLS, were possibly dissociated by catalytic reaction of Bi atoms.

In this paper, we first fabricated a nanoPt modified platinum electrode. Then through a simple method, the electrode surface was introduced with a submonolayer of bismuth that acted as an effective promoter. Cyclic voltammetry and other characterizations were employed. The obtained Bi^III/nanoPt/Pt electrode exhibited two greatly increased oxidation peaks at negative and positive potential areas, respectively. The signals were far larger than that of platinum electrode because of the large true surface area of nanoparticles and the catalysis of bismuth adsorbed on platinum. In the presence of bismuth, the platinum active sites could combine with more OH^- from bismuth hydroxyl to form a new active site for the oxidation of glucose. The prepared Bi^III/nanoPt/Pt electrode given high sensitivity and excellent linearship to glucose detection and showed the potential application in the areas of electrocatalysis or electroanalysis.

In this work, we discuss the growth of dilute InAsBi nanostructures grown by metalorganic vapor phase epitaxy on GaAs substrates. The surface morphology of InAsBi nanostructures is carefully investigated, as a function of the growth temperature, by scanning electronic microscopy and atomic force microscopy. (004) High-resolution X-ray diffraction configuration has been used to characterize the crystalline quality and Bi incorporation in the InAsBi films. Low temperature and low Bi flow favor the formation of elongated nanostructures during growth. We give a quantitative description of the elemental processes for the formation of these nanostructures. Our description is based on the Tersoff and Tromp theoretical model.

In this study, $\mathrm{\text{bismuth}}+\mathrm{\text{carbonate}}$ co-doped and pure hydroxyapatites (HAp) were coated on rough surfaces of Ti6Al4V plates by biomimetic method. Prepared samples were investigated with SEM, EDS, FTIR, XRD and ICP. Furthermore, mechanical scratch tests, profilometer tests and in vitro cell studies were carried out. In order to explore the antibacterial characteristics of the coating, the survival rate of a bacteria named Staphylococcus epidermidis was determined. Structural investigations showed that HAp nucleation began four days after the immersion, expectedly nucleation developed collaterally with the incubation period and co-dopants had considerable effect on surface characteristics. Besides, the pretreatment procedure and dopants had notable impact on mechanical qualifications of the coatings. The critical load values obtained for coating failure were detected above 100mN in all types of coatings (max. critical load was obtained from 0.3mM co-doped coatings). Cancerous bone cells (SaOS-2) on prepared coatings were evaluated in terms of biological properties. 0.1-C7 and 0.3-C7 exhibited highest reduction percentage among all co-doped samples. Further increase in dopants concentrations up to 0.5mM lead to increase in toxicity and decrease in cell proliferation. Antibacterial test results showed the most antibacterial samples were 0.1-C7 and 0.3-C7, the results conformed with cell culture findings.

As ²¹³Bi, a spontaneous alpha-emitting radioisotope, and ¹⁰B, a neutron-activated source of alpha particles, have been found to be potential tools in the treatment of cancer patients, a novel bismuth porphyrin, bearing both boron atoms and a strap with a hanging carboxylic group, was synthesized.

A comparative study of bismuth complexation by various porphyrins which differ according to the structural scaffold – either picket(s) or strap(s) – that deliver the carboxylic acid groups close to the metal, has been performed. Unlike strapped porphyrins, and although more flexible, the picket ligands do not lead to more stable bismuth complexes.

This account summarizes how the binding properties of a regular porphyrin macrocycle for large cations can be significantly modified and even tuned when the surrounding skeleton delivers at least one carboxylic acid group close to the N-core. While kinetics of metal insertion are drastically improved, unique dinuclear species can be obtained with a possible control of the nuclearity. The first incorporation of an α-core emitter radioisotope of particular interest for cancer therapy was recently demonstrated. All in all, this overhanging carboxylic acid strategy can be regarded as an alternative to either expanded porphyrins for the coordination of large cations from groups 14–15 (Pb^II, Bi^III) or contracted and isomeric porphyrins for the coordination of smaller cations from group 12 (Hg^II)

This minireview highlights the unusual coordination geometries observed in bimetallic complexes of mercury, thallium, lead and bismuth. These bimetallic complexes remain scarce and through an analysis of their X-ray structures, the various structural features that favorise them will be underlined.

Bismuth has a great potential as the anode for sodium-ion batteries (SIBs) because of the layered structure with large interlayer space, long mean free path, and high volumetric capacity. In this paper, carbon-coated bismuth (Bi@C) core-shell nanostructure has been in situ synthesized by one-step direct current (DC) arc discharge method for the first time. The Bi@C nanocomposite without further decoration or any other treatment exhibits superior electrochemical performance as anode for SIBs and delivers stable capacities of 356, 342, 334, 327, 325, 323, and 318mAhg${}^{-1}$ at the current densities of 0.2, 0.5, 1, 3, 5, 7 and 10Ag${}^{-1}$, respectively. There is no obvious decay after 630 cycles with a capacity of 291mAhg${}^{-1}$ at 10Ag${}^{-1}$, showing the excellent rate capability and long cycle stability in SIBs. Electrochemical tests proved that the ultra-fast charge–discharge performance is related to the fast redox kinetics of Na${}^{+}$ in layered structure of bismuth crystal. The Na${}^{+}$ storage mechanism of Bi@C nanocomposite anode was also investigated by cyclic voltammetry and in situ XRD. Based on experimental data, this paper proves that the arc discharge method is a simple and efficient method for preparing nanoscale electrode materials.

Bi/Bi₂MoO₆ composite was prepared via a facile one-step hydrothermal reduction method and its photoelectric property was investigated. During the solvent-controlled reaction process, lysine performed as the reductant to in situ reduce Bi${}^{3+}$ to metallic Bi. XRD, SEM, TEM, HRTEM, XPS and FT-IR were used to characterize the morphology, structure and chemical composition of the samples obtained. Bi/Bi₂MoO₆ composites have special structure of Bi₂MoO₆ nanosheets surrounding on the surface of Bi microspheres, besides, the Bi₂MoO₆ nanosheets have a thickness of 10–20nm. Furthermore, electrochemical test results show that the Bi/Bi₂MoO₆ composites can significantly enhance the separation efficiency of photogenerated charge carriers, the photocurrent of Bi/Bi₂MoO₆ composites prepared with 4mmol lysine is about 15 times to pure Bi₂MoO₆.

Effects of bismuth and antimony additions on the microstructure and mechanical properties of Mg-9Al-0.8Zn-0.2Mn (AZ91) alloy have investigated. The results indicated that small amount of bismuth or antimony additions to the alloy of AZ91 results in significant increases in yield strength and creep resistance but slight decreases of ductility at elevated temperatures up to 200 °C. The highest creep resistance has been obtained from the alloy with combined additions of bismuth and antimony. Microstructural observations reveal that the additions of bismuth or antimony have the effect on refining the β (Mg₁₇Al₁₂) precipitates in the as-cast alloys and suppressing discontinuous precipitation of the β phase effectively during aging process. Some needle-shaped Mg₃Bi₂ or Mg₃Sb₂ particles distributed mainly at grain boundaries have been observed in the alloys with bismuth or antimony additions. Both of Mg₃Bi₂ and Mg₃Sb₂ have high thermal stability at elevated temperatures and play important roles of improving creep resistance of the alloys at elevated temperatures.

We theoretically study quantum phase transitions between the quantum spin Hall and insulator phases, both of which are insulating in the bulk. This gives us an alternative view to the topological order in the quantum spin Hall phase. We also explain our theoretical proposal of the ultrathin bismuth film as a candidate to the 2D quantum spin Hall system.

Hall effects of bismuth have been studied theoretically with a special reference to the diamagnetic susceptibility. The conductivity, the Hall conductivity, and the orbital susceptibility are calculated on the basis of the Kubo formula for the 4 × 4 Dirac fermions in three dimension. The Hall coefficient exhibits unexpected peaks at the band-edge and sign change at the center of the band gap. Implications of the present results to bismuth alloys are discussed.

We report a theoretical calculation explaining the quantum Nernst effect observed experimentally in a bismuth single crystal. Generalizing the edge-current picture in two dimensions, we show that the peaks of the Nernst coefficient survive in three dimensions due to a van Hove singularity. We also evaluate the phonon-drag effect on the Nernst coefficient numerically. Our result agrees with the experimental result for a bismuth single crystal.