Amounts Of Bismuth Research Articles

Effect of bismuth additives on the thermophysical properties and thermodynamic functions of aluminum alloy AlFe5Si10

The temperature dependence of the heat capacity of the aluminum alloy AlFe5Si10 with bismuth was studied in the “cooling” mode. It is shown that with increasing temperature, the heat capacity, enthalpy and entropy of alloys increase, and the value of the Gibbs energy decreases. As the amount of bismuth in the initial alloy increases, the heat capacity, enthalpy and entropy of the AlFe5Si10 alloy decrease, while the value of the Gibbs energy increases.

Surface-Enriched Room-Temperature Liquid Bismuth for Catalytic CO2 Reduction.

Bismuth-based electrocatalysts are effective for carbon dioxide (CO2) reduction to formate. However, at room temperature, these materials are only available in solid state, which inevitably suffers from surface deactivation, declining current densities, and Faradaic efficiencies. Here, the formation of a liquid bismuth catalyst on the liquid gallium surface at ambient conditions is shown as its exceptional performance in the electrochemical reduction of CO2 (i.e., CO2RR). By doping a trace amount of bismuth (740ppm atomic) in gallium liquid metal, a surface enrichment of bismuth by over 400 times (30 at%) in liquid state is obtained without atomic aggregation, achieving 98% Faradic efficiency for CO2 conversion to formate over 80 h. Ab initio molecular simulations and density functional theory calculations reveal that bismuth atoms in the liquid state are the most energetically favorable sites for the CO2RR intermediates, superior to solid Bi-sites, as well as joint GaBi-sites. This study opens an avenue for fabricating high-performing liquid-state metallic catalysts that cannot be reached by elementary metals under electrocatalytic conditions.

Lubrication properties of gallium-based liquid metals by doping bismuth

Ga-based liquid metal (GLM) is a promising high temperature lubricant but its lubricating properties still need to be further improved. In this work, the lubrication properties of bismuth doped Ga-base liquid metal in a vacuum environment were studied in a wide temperature range from room temperature (RT) to 600 °C, where the self-mated Inconel 625 alloy sliding-pairs were selected. The results indicate that the addition of a small amount of bismuth (0.5 wt%) in GLM can enhance its lubricating performance by suppressing the oxidation of gallium within the temperature range of 200 °C to 600 °C, thereby decreasing the wear of Inconel 625 alloy.

Photoinduced transformations in (As1–xBix)2S3 glass observed by Raman spectroscopy

AbstractRaman spectra of (As1–xBix)2S3 glass samples with x ≤ 0.2 measured at the excitation with above‐bandgap (532 nm) laser light at a relatively low power density (Pexc = 4 kW/cm2) clearly confirm the amorphous character, thereby markedly extending the known compositional interval of existence of the (As1–xBix)2S3 glass previously known (x ≤ 0.06). Spectra measured at an increased Pexc (40 kW/cm2) reveal a photostructural transformation in the illuminated area of the glass leading to an additional contribution of Bi–S bonds as well as to an increasing number of cage‐type As4S4 units with homopolar As–As bonds. A number of new features in a broad range up to about 1,000 cm−1, which emerge in the Raman spectra of the (As1–xBix)2S3 glasses with high (x ≥ 0.14) Bi content and increase in intensity with the exposure time, are related to a photochemical transformation, namely, oxidation of arsenic and sulphur on the (As1–xBix)2S3 glass surface with formation of units containing arsenate AsO43− and sulphate SO42− ions. These processes are irreversible and occur only in the presence of a sufficient amount of bismuth.

Bismuth release from endodontic materials: in vivo analysis using Wistar rats

Calcium silicate-based materials are used to block the communication between the root canal and the periodontal ligament space. This brings the materials into contact with tissues and the potential for local and systemic elemental release and movement. The aim of the study was to evaluate the elemental release of bismuth from ProRoot MTA in contact with connective tissues after 30 and 180 days as well as any accumulation in peripheral organs using an animal model. Tricalcium silicate and hydroxyapatite containing 20% bismuth oxide (HAp-Bi) were used as controls. The null hypothesis was that bismuth migrates from tricalcium silicate-based materials when associated with silicon. The materials were examined using scanning electron microscopy, energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction prior to implantation as well as using SEM/EDS, micro X-ray fluorescence and Raman spectroscopy after implantation to assess elemental presence in surrounding tissues. Histological analysis was used to evaluate the changes in tissue architecture and inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the elemental deposition. For the systemic investigation, routine blood analysis was performed and organs were obtained to evaluate the presence of bismuth and silicon using ICP-MS after acid digestion. In the histological analysis of the implantation sites, macrophages and multinucleated giant cells could be observed after 30 days which after 180 days became a chronic infiltrate; although, no major differences were identified in red and white blood cell analyses and biochemical tests. Implantation altered the materials as observed in the Raman analysis and bismuth was detected both locally and within kidney samples after both periods of analysis, indicating the potential for accumulation of bismuth in this organ. Smaller amounts of bismuth than observed in the kidney were also detected in blood, liver and brain for the ProRoot MTA and HAp-Bi after 180 days. Bismuth was released from the ProRoot MTA locally and was detected systemically and in samples without silicon; thus, the null hypothesis was rejected. The bismuth release demonstrated that this element accumulated both locally and systemically, mainly in the kidneys in comparison with brain and liver regardless of the material base.

A fast‐integrated x‐ray emission spectrometer dedicated to the investigation of Pt presence in gold Celtic coins (3rd–1st century BCE)

AbstractWith this study, we present the development of a transportable x‐ray emission spectrometer (XES) that was realized in a net time of 20 h, in order to verify the presence of Platinum (Pt) in gold Celtic coins belonging to 3rd–1st century BCE. Prior to the XES study, measurements using Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM‐EDS) revealed that the coins were made of highly concentrated gold (Au) alloy with trace amounts of bismuth (Bi) and, in one case, osmium (Os) and iridium (Ir). Os and Ir together with Pt and other components belong to the Platinum Group Elements (PGE). They form inclusions in ancient gold alloys and their presence is significant in provenance studies since they indicate the use of alluvial gold. Detection of platinum trace elements in a golden matrix is not possible using energy dispersive x‐ray emission techniques (SEM‐EDS, ED‐XRF, or PIXE) because of the limited energy resolution of the Si detectors. A way to overcome this problem is by using a high‐resolution wavelength dispersive x‐ray emission technique. For this purpose, we built a crystal spectrometer in Von‐Hamos geometry. In the framework of this study three samples/coins have been measured, and the presence of Pt was verified in one of them. The limitations of our spectrometer are critically evaluated and ways to optimize the performance of the spectrometer are discussed.

Intervalley energy separation in the conduction band of InAs1−x Bi x determined by terahertz emission spectroscopy

InAsBi layers with different bismuth content were grown on InAs substrates by solid source MBE. The amount of bismuth incorporated in the layers was estimated using X-ray diffraction measurements. The relaxation degree of the grown crystalline layers was evaluated using reciprocal space map analysis. The intervalley energy separation in the conduction band of InAsBi was studied by Terahertz Excitation Spectroscopy. It has been found that this separation slightly decreases with increasing Bi content. In the studied samples with Bi content varying from 2.7% to 4.5% the Γ-L separation shifts down to about 0.9 eV.

Understanding the physical, optical and gamma ray shielding properties of the PbO-Bi2O3-CdO-B2O3 glass systems

Physical properties, optical properties, and shielding properties were reported herein by varying the amount of bismuth (III) oxide (Bi2O3) and boron oxide (B2O3) on the PbO-Bi2O3-CdO- B2O3 glass systems through Melt quenching technique. After altering the amount of Bi2O3 density studied glass systems have varied from 4.3 g/cm3 - 5.7 g/cm3. With the addition of bismuth oxide, the density, molar volume, and oxygen packing density all rise. As bismuth concentration increases, the indirect band gap reduces, indicating structural changes in the glasses. As bismuth concentration rises, so do the refractive index (n), optical dielectric constant, and reflection loss (RL) characteristics. Ionic nature of current samples is supported by the reduction in electronegativity and rise in polarizability, which reduces the band gap. Linear attenuation coefficients (LAC), mass attenuation coefficients (MAC), half value layers (HVL), and mean free path (MFP) were calculated for photon energy range 0.015–15 MeV via exploiting Phy-X software. Containing supreme amount of Bi2O3 (25% mol) studied glass systems have shown higher values of effective atomic number (Zeff), LAC, MAC along with least values of HVL and MFP considering with other studied glass systems. Results showed that deposition of Bi2O3 on the studied glass systems has boosted their shielding ability.

Electrochemical degradation of doxycycline hydrochloride on Bi/Ce co-doped Ti/PbO2 anodes: Efficiency and mechanism

Doxycycline hydrochloride (DOX), a widely used broad-spectrum antibiotic, was used in large quantities and its residues in the environment caused a series of environmental problems. In this study, small amounts of bismuth (Bi) and cerium (Ce) were co-doped in the titanium matrix lead dioxide anode (Ti/PbO2) using the electro-deposition method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used for the characterization of the electrodes. And the prepared PbO2 anode was found to be mainly composed of β-PbO2, and Ti/PbO2/Bi-Ce 03 (co-doped with 0.5 mmol·L−1Bi and 0.5 mmol·L−1 Ce in PbO2 anodes) had the best catalytic effect and surface structure. Compared with Ti/PbO2, doping improved its corrosion potential (21.82%), accelerated lifetime (108.33%), and degradation efficiency (43.62%) while reducing the electrochemical impedance (17.91%). It was proved by a single-factor experiment that the degradation rate of DOX was 100% at 10 min with a current density of 10 mA·cm−2, electrolyte concentration [Na2SO4]= 0.1 mol·L−1, and pH= 4, which was the best degradation condition for DOX. In addition, the degradation of DOX fitted the first-order kinetic equation. The DOX degradation on Ti/PbO2/Bi-Ce 03 electrode was mainly attributed to direct oxidation and SO4•-. Four possible degradation pathways were postulated using the results of high-performance liquid chromatography-mass spectrometry (HPLC-MS). The paper provided a new way for preparing Ti/PbO2 electrodes with high catalytic activity and longer lifetime, and also an efficient way for degradation of antibiotic DOX.

Synthesis of the Bi2GeO5 Ferroelectric Crystalline Phase from a Nonstoichiometric Batch

In the present research, an individual Bi2GeO5 crystalline phase is successfully synthesized on air from Bi2O3‐Bi‐GeO2 batch in which some part of bismuth oxide is replaced by metallic bismuth to create an oxygen deficiency. The crystallization process is carried out by three methods: heterophase synthesis, melt cooling, and glass crystallization. The structure of the formed crystalline phases as well as the influence of the bismuth metal quantity and synthesis temperature on crystallization results have been investigated by X‐ray diffraction (XRD). It is found that both the melt temperature rising, and an increase of metallic bismuth amount led to the formation of an individual Bi2GeO5 phase. The optimal initial batch compositions and crystallization conditions to produce an individual Bi2GeO5 or Bi4Ge3O12 phase have also been found.

Significantly reduced conductivity in strontium titanate-based lead-free ceramics by excess bismuth

Lead-free dielectric ceramics 0.75SrTiO3-0.25BiFeO3 (ST-BF) with an extra amount of bismuth (Bi) are synthesized by the conventional solid-state reaction method. The crystal structures of ST-BF retain pseudo-cubic phase as Bi content increases. The grain size is found to significantly increase from 1.8 to 4.9 µm and then fall to 3.3 µm in the presence of excess Bi, exhibiting a distinct heterogeneous core–shell microstructure. Impedance spectroscopy data indicates that with increasing excess Bi content to 2 mol%, the shell resistivity increases significantly to ∼ 9 MΩ cm with the largest volume fraction of the shell/core area, and both the core and shell activation energies are increased, resulting in reduced dielectric loss of ∼ 0.08 at 1 kHz and high breakdown strength of ∼ 140 kV cm−1. This work provides a potential strategy for further improvement of ST-BF for capacitor applications.

Room‐temperature laser operation of a (Ga,In)As/Ga(As,Bi)/(Ga,In)As W‐type laser diode

The ongoing pursuit for laser device emitting in the near-infrared spectral region on GaAs substrates has led to various material systems and device concepts. Alloys containing dilute amounts of Bismuth are promising candidates due to the already substantial band gap shift when incorporating low molar fractions of Bi in the GaAs host lattice. However, devices emitting at technologically essential wavelengths of 1.3 and 1.55 μm have yet to be demonstrated using this material system. Especially the non-equilibrium nature of the growth conditions required to grow the metastable material makes epitaxial growth with high molar fractions of Bi challenging. An alternate approach to reach the desired wavelengths exploits a type-II band alignment between two materials to push the emission wavelength further into the telecom bands. Here, room-temperature laser operation of the first type-II structure employing Ga(As,Bi) as hole confining layer and (Ga,In)As as electron confining layer is demonstrated. Sample growth is conducted by low-pressure metalorganic vapour phase epitaxy. Broad area laser devices are processed and characterized by electroluminescence measurements. A threshold current density of 3.86 kA/cm2 and emission wavelength of 1037 nm are observed, showing this device concept's potential for future lasers in the telecom bands.

2-Mercaptobenzothiazole modified carbon paste electrode as a novel copper sensor: An electrochemical and computational study

In this work a novel selective sensor for copper based on a carbon paste electrode modified with 2-mercaptobezothiazole (CPE-MBT) using square wave anodic stripping voltammetry (SWASV) is presented. Parameters such as pH, potential and deposition time, amount of bismuth, etc. were optimized to have a selective and quantitative detection of copper, even in the presence of other metals and common interferences. The results showed a detection limit of 0.71 ppm and a quantification limit of 83.177 µA/cm2 with good repeatability and reproducibility. Additionally, the sensor was successfully applied to the analysis of water samples. Density functional theory and atoms in molecules calculations agree with the experimental results, providing insights on the modified electrode’s surface.

ATLAS 2011

Abstract Atlas 2011 is a wrought, heat-treatable, aluminum-copper alloy (2xxx series) that also contains small amounts of bismuth and lead. Both bismuth and lead promote high-speed machining by causing the chips to fracture during machining and breaking away from the cutting tool. Atlas 2011 is used in applications where good machinability and high strength are required. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-472. Producer or source: Atlas Steels.

Synthesis and characterization of Bi-doped g-C3N4 for photoelectrochemical water oxidation

Photoelectrochemical (PEC) water splitting has emerged as a promising technology for the storage of renewable energy sources, via the production of hydrogen, a clean and multi-purpose chemical energy vector. The key component in a PEC cell is the photoanode where light energy is absorbed and transformed into electron-hole pairs of appropriate energy for water photo-oxidation. We report on the synthesis of g-C3N4 materials, with an elongated nano-structure, fabricated by the direct pyrolysis of supramolecular melamine used as a chemical precursor. The as-prepared material was used to host specific amounts of bismuth, a doping element used to adjust the band gap of the hosting matrix. The presence of Bi in the photoanodes was confirmed by energy dispersive x-ray analysis (EDX) analysis. Powder X-ray (p-XRD) and Fourier transform infrared (FT-IR) measurements performed on the photoanodes confirmed the absence of Bi-based oxides, and showed that bismuth may bonded to nitrogen atoms inside the voids of the g-C3N4 skeleton. Differential reflective spectroscopy (DRS) measurements revealed that the band gap energy was reduced upon introduction of Bi into g-C3N4. From photoluminescence (PL) plots, it was observed that the 2.5% Bi doping induced a 6-fold electron-hole separation, compared to the pristine g-C3N4. PEC water splitting measurements showed that 2.5% Bi doping approximately doubled the activity of g-C3N4 towards water oxidation. Electrochemical impedance spectroscopy (EIS) measurements showed that Bi doping was an effective method for decreasing the charge transfer across the electrode/electrolyte interface; 2.5% Bi-g-C3N4 was reduced by around 2.4 times compared to that of pristine g-C3N4. Bode-phase plots accompanied EIS spectra revealed that the lifetime of the photo-generated electrons in neat g-C3N4 was improved as a result of Bi doping. The band gaps and the positions of the valence and conduction bands were determined from Mott–Schottky plots.

High performance of Bi3+ and Cl− co-doped Li3V2(PO4)3 as cathode for lithium-ion batteries

Bismuth (III) (Bi3+) and chloride (Cl−) ion co-doped Li3V1·97Bi0·03(PO4)3−x Cl x /carbon (C) compounds (x = 0·03, 0·05, 0·07, 0·09) were prepared by way of a simple sol–gel method. The X-ray diffraction patterns proved that a small amount of bismuth (III) and chloride ion doping does not change the crystal structure of lithium vanadium phosphate (Li3V2(PO4)3). Charge/discharge results showed that bismuth (III) and chloride ion co-doped samples exhibited higher initial capacities than lithium vanadium phosphate/carbon. Li3V1·97Bi0·03(PO4)2·95Cl0·05/carbon demonstrated the highest capacity of 188 mAh/g at 0·1 C. The cycling performance at 1 C showed that the capacity retention of Li3V1·97Bi0·03(PO4)2·95Cl0·05/carbon reaches 81·31% after 300 cycles. Electrochemical impedance spectroscopy and cyclic voltammetry testing indicated that Li3V1·97Bi0·03(PO4)2·95Cl0·05 has the smallest charge-transfer resistance and the largest lithium-ion (Li+) diffusion coefficient. The improvement can be assigned to the enhanced kinetics of lithium ions, reduction in polarization and decreased charge-transfer resistance of the electrode.

Consequences of Bi3+ introduction for Pr3+ in PrAlO3

With the intent to comprehend the structure and hence the property changes in the PrAlO3 system, the substitution of Bi3+ for Pr3+ has been attempted. The samples were synthesized by solution combustion synthesis and characterized extensively. X-ray diffraction studies revealed that the rhombohedral perovskite structure was preserved up to 20 mol% substitution of bismuth, beyond which diffraction peaks of the secondary phase of α-Bi2O3emerged. The structural refinements indicated the increment of both a and c lattice dimensions with an increase in bismuth content. The samples had porous morphology, and a mean pore diameter of 22.4 nm, along with a surface area of 100 m2/g, was deduced from BET measurements for the 20 mol% bismuth-substituted sample. FTIR, Raman spectroscopic and electron microscopic analysis reinforced the perovskite structure adopted by the bismuth-substituted samples. Both Pr and Bi in Pr0.80Bi0.20AlO3 existed in the + 3 oxidation state as established from the XPS analysis. The inclusion of bismuth introduced intermediate energy levels within the bandgap, as suggested by the redshift of the absorption edge for the bismuth-substituted samples. As the optical bandgap values were in the semiconductor regime, the application of bismuth-replaced samples as a catalyst for the photodegradation of crystal violet dye solution was demonstrated. The amount of dye degraded increased with an increase in the amount of bismuth in the sample. Additionally, Pr0.80Bi0.20AlO3 catalyzed the reduction of nitroaromatics promoted possibly by the Bi3+/Bi(0) redox couple.

In situ analysis of Bi terminated GaAs (0 0 1) and Ga(As,Bi) surfaces during growth by MOVPE

The influence of trimethylbismuth (TMBi) on the GaAs (001) surface reconstruction is studied in situ by reflection anisotropy spectroscopy (RAS) in a metal organic vapor phase epitaxy (MOVPE) system. During supply of TMBi the RAS spectra indicate a change of the arsenic rich c(4 × 4)β surface reconstruction to a bismuth terminated surface reconstruction. This Bi terminated surface is correlated to the current understanding of growth mechanisms for III/V semiconductors containing small amounts of bismuth. The formation, thermal stability and influence of the ambient conditions on this surface is analyzed. The RAS results are correlated to mass spectrometric studies with a real time fast Fourier transform quadrupole ion trap mass spectrometer (iTrap), which is used inline in the same MOVPE system. Both results indicate an about 40 °C lower decomposition temperature of TMBi compared to TBAs. The decomposition temperatures are determined by mass spectrometry with 290 °C for TMBi and 330 °C for TBAs. Furthermore, the surface reconstruction is studied during growth of Ga(As,Bi) bulk layers grown on GaAs. Under ideal conditions, the RAS measurement of the Ga(As,Bi) growth surface shows the signal of a c(4 × 4)β surface reconstruction which is shifted to lower energies as compared to the GaAs surface reconstruction.

Morpho-structural and electrical characterization of Bi-doped apatite-type lanthanum silicates prepared by gel-combustion

La10−xBix(SiO4)6O3 ceramics (x = 0; 0.1; 0.15; 0.2; 0.3) were obtained from precursors prepared by gel combustion using l-aspartic acid as fuel. This study presents the effect of Bi3+ doping level and sintering temperature on the morpho-structural and electrical properties of apatites. Processes involved in the apatite formation same as crystallization temperature were examined through TGA. The XRD patterns have showed that all samples adopt the apatite structure and crystallize in the hexagonal space group P-3(147). Samples crystallite size varies between ~ 58 and ~ 118 nm depending on the Bi3+ doping level and the sintering temperature. In order to explain the conduction in apatite, the preferential position of Bi3+ in lattice and the occupancy factors of O5, O6 were calculated by Rietveld refinement. ICP-OES and XPS measurements give the bismuth amount accommodated in apatite lattice and its oxidation states. The morphology, homogeneity and compactness of the ceramics at different Bi doping level were examined through SEM. The relative density of the material is enhanced by the sintering temperature up to 1500 °C, reaching 91.63% for sample doped with 1.5% Bi. Through EIS investigations, the conductivities at 500 °C, for sample doped with 1.5% Bi, are: 9.22 × 10−5 Scm−1 (sintered at 1400 °C) and 1.02 × 10−3 Scm−1 (sintered at 1500 °C), respectively, values which are higher than that of un-doped apatite (6.46 × 10−5 Scm−1).

Effect of bismuth incorporation on thermal properties of quaternary chalcogenide glass Se80Te15-xCd5Bix (x=0,5,10) alloys

Differential scanning calorimetry has been employed to investigate the thermal properties of Se80Te15-xCd5Bix (x = 0, 5, 10) glass system. The Variation of characteristic temperatures such as glass transition temperature (Tg), onset crystallization temperature (Tc), peak crystallization temperature (Tp) and melting temperature (Tm) are studied as a function of composition and heating rate. A stepwise increase in values of characteristic temperatures has been observed with the increase in heating rate. Further, obtained values of characteristic temperatures display decreasing trend with increase in bismuth concentration. The compositional and heating rate dependence of Thermal parameters such as glass forming ability (ΔT), thermal stability (Hg), enthalpy (ΔH) and entropy (ΔS) has been investigated. It has been observed that ΔT and Hg have lowest and highest values for Se80Te5Cd5Bi10 and Se80Te15Cd5 compositions respectively. Avrami index (n) and activation energy for crystallization (Ec) have been calculated for all the samples. Values of n obtained for Se80Te15Cd5, Se80Te15Cd5 Bi5 and Se80Te5Cd5Bi10 compositions are found to be 1.44, 2.16 and 2.16 respectively. Based on the obtained values of n, the nucleation process in alloys is discussed. It is noteworthy to mention that least value of Ec is observed for the alloy Se80Te5Cd5Bi10 containing the highest amount of bismuth. Furthermore, calculated thermal parameters are used to anticipate the electrical switching behavior of the alloys.