Tin Impurity Research Articles

Advanced tin recycling technology

The article gives compositions of tin alloys and tin of the highest and first quality categories. The main impurities in tin, tin babbit and tin‑lead solders are presented. The technique of removing copper from POSM 61M solder for producing POSM 61solder by filtration is described.

Impact of d-states on transition metal impurity diffusion in TiN

In this work, we studied the energetics of diffusion-related quantities of transition-metal impurities in TiN, a prototype ceramic protective coating. We use ab-initio calculations to construct a database of impurity formation energies, vacancy-impurity binding energies, migration, and activation energies of 3d and selected 4d and 5d elements for the vacancy-mediated diffusion process. The obtained trends suggest that the trends in migration and activation energies are not fully anti-correlated with the size of the migration atom. We argue that this is caused by a strong impact of chemistry in terms of binding. We quantified this effect for selected cases using the density of electronic states, Crystal Orbital Hamiltonian Population analysis, and charge density analysis. Our results show that the bonding of impurities in the initial state of a diffusion jump (equilibrium lattice position), as well as the charge directionality at the transition state (energy maximum along the diffusion jump pathway), significantly impact the activation energies.

Эластопроводимость германеновых нанолент с изоморфными дефектами замещения

The results of the theoretical study of the impurity germanium nanoribbons piezoresistance are demonstrated in this article. The nanomaterial contains point isomorphic substitution defects of different concentrations of two types of isomorphic atoms of group IV: silicon (Si) and tin (Sn). The functions of the dependence of the longitudinal component of the elastic conductivity tensor on the magnitude of the strain of tension (compression), types and concentrations of defects are presented to study the characteristics of the piezoresistance effect. The results of the calculations show a qualitative agreement of the behavior of the piezoresistance constant of germanene nanoribbons for two types of isomorphic defects and with the literature data. Quantitative analysis allows us to conclude that the longitudinal component is higher in modulus in nanofilms with tin impurities, which indicates a more pronounced piezoresistance of the material. Conclusions are showed, that the impurity germanene with the tin atoms manifested more pronounced piezoresistance properties. It was be explained by high the electron mobility of the valence shell of this element compared to the germanium atom. This shell of the atom turns out to be more sensitive to deformations of the structure. Such material can be more effectively integrated as a basic element of semiconductor electronics devices due to the high susceptibility of its properties to the effects of deformations and the concentration of structural defects in accordance with this factor.

Effect of TiN Particle Size and Impurities on the Contact Resistance of TiN-Powder-Decorated Stainless-Steel Separator Electrodes for Fuel Cells

Effect of TiN Particle Size and Impurities on the Contact Resistance of TiN-Powder-Decorated Stainless-Steel Separator Electrodes for Fuel Cells

Physico‐chemical properties of international simple glass (ISG) nuclear waste simulants: Luminescence baseline study

AbstractBorosilicate glass has been adopted internationally for the treatment of nuclear waste with the object of long‐term stabilization through vitrification. Aiming to facilitate experimental comparisons across laboratories, the six‐component international simple glass (ISG) was developed as benchmark. The original ISG produced by Mo‐SCI Corporation (Rolla, MO) was distributed and characterized for different physical properties thus serving as reference for further studies. Still, photoluminescence (PL) properties, which may be useful for scrutinizing radiation‐induced damage, have not been reported. Further, the original ISG contained significant iron impurities, which may present interference in various studies (e.g., optical). Consequently, two new ISG analogs lacking iron impurities (labeled ISG‐1 [closest composition to original ISG] and ISG‐2 [some MgO added at expense of CaO]) were synthesized by Corning Inc. (Corning, NY) (also doped with lanthanum for subsequent corrosion tests involving atom probe tomography), which remain to be fully characterized. Accordingly, this work was undertaken to perform a comprehensive study comparing the three ISG specimens. Various characterizations were then performed on the pristine glasses: X‐ray diffraction and vibrational spectroscopy (structural properties); static‐leach product consistency test (PCT, dissolution behavior); dilatometry and calorimetry measurements (thermal properties); and optical absorption with Tauc and Urbach plots analysis, followed by PL spectroscopy with decay kinetics assessment (optical properties). While the general structural features appeared similar among the glasses, the deconvolution of Raman spectra suggested a lower degree of connectivity in the silica network for ISG‐2. In addition, some differences were indicated from the PCT results and thermal properties assessed, which were discussed based on compositional variations. Further on, the optical properties were shown to be the most distinct. The optical absorption of the original ISG was characterized by Fe2+/Fe3+ impurities not detected for ISG‐1 and ISG‐2. The glasses all exhibited two main PL features (∼1.8 and 2.5 eV) with multiexponential decay behavior apparently of intrinsic origin. In addition, ISG‐1 and ISG‐2 showed a third high‐energy (∼3.4 eV) fast‐decaying contribution tentatively credited to tin impurities, which appeared most significantly for ISG‐1. The results are expected to serve as baseline for future studies simulating the effects of radioactive element decay.

Effect of heat treatment processes on the microstructure and mechanical properties of low alloy structural steels with different impurity tin contents

ABSTRACT Conventional quenching and tempering (CQ-T) process does not always ensure the achievement of desired toughness of the steels with residual element tin. In the present work, a novel intercritical heat treatment (Q-IQ-T) process consisting of quenching (Q), intercritical quenching (IQ) and tempering (T) is adopted. The results show that the microstructure of the Q-IQ-T specimens consists of tempered martensite (M) and ferrite (F), which is finer than the full martensitic microstructure of the CQ-T specimens. 0.03%, 0.06% and 0.09% tin contents reduce the impact energy values of CQ-T specimens by 22.95%, 29.61% and 45.93%, respectively, while those of the Q-IQ-T specimens decrease by 19.25%, 17.32% and 21.32%, respectively. Together with comparison to the CQ-T specimen with 0.09% tin, the impact energy value of Q-IQ-T specimen increases by 85.24%, from 40.86 J to 75.69 J. And the fracture morphology changes from brittle fracture to ductile fracture.

Substitutional Tin Acceptor States in Black Phosphorus

Nominally-pure black phosphorus (BP) is commonly found to be a p-type semiconductor, suggesting the ubiquitious presence of impurity species or intrinsic, charged defects. Moreover, scanning tunnelling microscopy (STM) images of black phosphorus reveal the presence of long-ranged double-lobed defect features superimposed onto the surface atomic lattice. We show that both the p-type doping of BP and the defect features observed in STM images can be attributed to substitutional tin impurities. We show that black phosphorus samples produced through two common synthesis pathways contain tin impurities, and we demonstrate that the ground state of substitutional tin impurities is negatively charged for a wide range of Fermi level positions within the BP bandgap. The localised negative charge of the tin impurities induces hydrogenic states in the bandgap and it is the 2p level that sits at the valence band edge that gives rise to the double-lobed features observed in STM images.

In English

It is known that titanium dioxide as photocatalyst has significant drawback - limited absorption spectrum in the ultraviolet region makes it impossible to use solar energy. To expands the absorption spectrum of TiO2, the doping of impurities (metal, non-metal, etc.) were used. They affected the electronic structure and spectral characteristics of TiO2. The aim of our work was to investigate the influence of tin impurities on spectral characteristics of titanium dioxide using experimental and theoretical methods. The TiO2 powders modified by different amount of tin (Sn/TiO2) were synthesized by sol-gel method. The samples were characterized by SEM, EDX, FT-IR and UV-VIS spectroscopy. It has been found that Sn/TiO2 consists of fragmented agglomerates in the range of 5–10 mm. EDX spectroscopy prove that powders include Ti, O and Sn elements. Modification of titanium dioxide with tin leads to band gap narrowing of samples, which explains by insertion of Sn atoms into crystal lattice of titanium dioxide, because Ti4+ and Sn4+ ions radii are close. The band gap values increased with increasing of tin content. The work also analyzes the vibrational spectra of Sn/TiO2 both experimentally and theoretically. In order to interpret the results obtained, quantum chemical calculations on the spatial and electronic structures of cluster models of titanium dioxide (anatase) with inserted tin atoms using the density functional theory B3LYP method and the basis set 6-31G (d, p) were carried out and the corresponding FT-IR spectra have been simulated. By comparing the experimental and theoretical results, the influence has been analyzed of the number and arrangement of impurity tin atoms in clusters on the observed IR spectra of the samples. This makes it possible to forgive the most probable structural motives of titanium dioxide particles doped with tin atoms, as well as to establish the fact of the presence of tin atoms in the samples. Based on the comparison of the IR spectra of samples with different numbers of tin atoms, it is possible to quantify their composition.

Ge(001) surface reconstruction with Sn impurities

Defects play an important role for surface reconstructions and therefore also influence the substrate growth. In this work we present a first principle calculation for the Ge(001) surface without and with tin impurities incorporated into the top surface layer. By mapping the system onto an Ising-type model, with interaction constants taken from density functional theory, the stability of the surface reconstructions under the influence of different concentrations of tin impurities is explored. This approach allows us to simulate the possible phase transitions for the different surface reconstructions including the local structure around the tin impurity atoms. In addition, we compare our theoretical results with experimental STM images on clean and Sn-doped Ge(100) surfaces.

Ammonia chloride assisted air-chlorination recovery of tin from pyrometallurgical slag of spent lead-acid battery

Tin-containing slag from pyrometallurgical recovery process of spent lead-acid battery is a valuable secondary Sn resource. However, the low content of Sn (~4 wt%) in this slag with complex impurities (Fe, Al, Pb, Zn, and Cu, etc.) makes it challenging for efficient tin separation. In this study, a low-temperature chlorinating process is proposed for tin recovery from the tin-containing slag by using ammonium chloride as the chlorinating reagent. Under the optimized chlorinating conditions, tin volatilization ratios of above 96% under both air and vacuum atmospheres could be achieved. However, the discrepancy between the temperatures of tin chlorinating and impurity metal chlorinating is more dramatic under the air atmosphere than that under vacuum, which facilitates the separation of impurities. Meanwhile, the decomposition rate of NH4Cl in air is much lower than that under vacuum atmosphere, resulting in less consumption of NH4Cl. The obtained chlorinated condensation product in air is subjected to a subsequent water leaching-alkali smelting-leaching-crystallization process to effectively separate Fe impurity and obtain the final sodium stannate product with a total tin recovery ratio of 94%. This study provides a promising strategy for the recovery of tin, and significant environmental benefit could be generated simultaneously with solid waste recycling.

Comparison of Radiochemical and Chemical Impurities in Liquid Wastes of Two Different 68Ge/68Ga Generators used in Nuclear Medicine PET Chemistry

Objectives:Germanium-68/gallium-68 (68Ge/68Ga) generator eluate contains a number of metal cations that can compete with 68GaCl3, reducing specific radioactivity. The first step in peptide labeling with 68GaCl3 is to remove 68Ge and several other metals with a long half-life. In this purification step, the elution residue that is passed through the cartridge is collected in glass waste bottles. Waste management is included in good production practices, and in particular, the activity of long half-life 68Ge (270.95 days) and other toxic metal levels need to be examined. Our objective in this study is to determine the 68Ge activity in liquid waste produced by the generation of 68Ga and heavy metal concentrations from the generator column materials and to assess whether it can be disposed of as normal waste.Methods:Liquid wastes produced by passing the 68Ge/68Ga generator eluate of 2 different identities via PSH+ cartridge have been analyzed with the inductively coupled plasma mass spectrometry device in the advanced technology application and research center of our university.Results:The average of the 68Ge radioactive pollution was estimated to be 0.142 ppm (μg.mL-1) in the liquid waste analysis after passing through the PSH+ cartridge in the pre-elution in the GalluGEN brand generator. While there was no tin (Sn) impurity, it was determined that the average zinc (Zn) was 1.95 ppm (μg.mL-1) and the average aluminum (Al) impurity was 10.95 ppm (μg.mL-1). While no 68Ge radioactive pollution was determined in the iThemba LABS brand generator, the average Sn was 0.098 ppm (μg.mL-1), average Zn 48.6 ppm (μg.mL-1), and average Al impurity 4.135 ppm (μg.mL-1).Conclusion:All 68Ge/68Ga generators produced have their own certificates. Metallic contamination in the postmarking waste of 68Ge/68Ga generators can be different. It would be a safe method to keep these wastes in place until they are dumped into the sewage systems, given their half-lives in terms of long half-life radioactive metallic contamination.

Archaeometric Provenance Constraints for Early Medieval Sparse Glazed Pottery from Donoratico (Livorno, Italy)

The study of a huge repertory of sparse glazed ware from Donoratico (Livorno, Italy) dated back to the ninth century was carried out to investigate the production technology via petrographic, chemical, and isotopic investigations. The mineralogical and chemical evidence suggested the application of a lead oxide flux to an unfired non‐calcareous ceramic body, in accordance with late Antique and early‐Medieval traditions. The isotopic investigation of the glazes also suggested different sources for PbO, which was frequently applied as a mix of different metal batches. The Pb isotopic record identified the Southern Tuscany districts (Campiglia Marittima and Colline Metallifere) and a source controlled by the Carolingian kings in the northern districts of Central Europe (either in Aquitaine or in the Middle German ore districts) as the most reliable sources. SEM‐EDS showed the presence of tin impurities in the form of secondary cassiterite agglomerates in most of the glazes obtained by the use of local lead. The presence of cassiterite veins in Southern Tuscany lead sulphide deposits was considered as the main cause for tin impurities in the glazing mixture and, thus, an important marker for the exploitation of local lead.

Sn(IV)-free tin perovskite films realized by in situ Sn(0) nanoparticle treatment of the precursor solution

The toxicity of lead perovskite hampers the commercialization of perovskite-based photovoltaics. While tin perovskite is a promising alternative, the facile oxidation of tin(II) to tin(IV) causes a high density of defects, resulting in lower solar cell efficiencies. Here, we show that tin(0) nanoparticles in the precursor solution can scavenge tin(IV) impurities, and demonstrate that this treatment leads to effectively tin(IV)-free perovskite films with strong photoluminescence and prolonged decay lifetimes. These nanoparticles are generated by the selective reaction of a dihydropyrazine derivative with the tin(II) fluoride additive already present in the precursor solution. Using this nanoparticle treatment, the power conversion efficiency of tin-based solar cells reaches 11.5%, with an open-circuit voltage of 0.76 V. Our nanoparticle treatment is a simple and broadly effective method that improves the purity and electrical performance of tin perovskite films.

Effect of the Segregation of Embrittling Impurities on the Local Strength of Grain Boundaries in a Martensitic Steel

The finite element method and the results of delayed fracture tests of Charpy specimens are used to determine the local strength of grain boundaries in 18Kh2N4VA steel at various contents of phosphorus, antimony, and tin impurities. The embrittlement of grain boundaries is attributed to the adsorption enrichment of grain boundaries in impurities in initial austenite, which leads to weakening of the intergranular cohesion. Phosphorus is found to have the highest susceptibility to intergranular segregation: during the same heat treatment, its grain-boundary concentration is higher than that in steel with antimony or tin. However, the segregation of antimony is more dangerous than the segregation of phosphorus, since, at its lower intergranular concentration, the local strength of grains of quenched steel decreases as in the case of phosphorus segregation.

Investigation of the structural, optical, and photoelectrochemical properties of α-Fe2O3 nanorods synthesized via a facile chemical bath deposition

In this study, a simple and cost-effective chemical bath deposition was employed to deposit nan-sized hematite (α-Fe2O3) directly on fluorine-doped tin oxide (FTO) substrates. The structure, morphology, and optical properties of α-Fe2O3 were manipulated by adjusting the experimental parameters, particularly the deposition temperature and precursor concentration. With increase in Fe precursor concentration from 0.1 M to 0.3 M, the surface morphology was changed from granular-shape condensed particles to vertically aligned rod-like structures. XRD spectra indicated signals from FTO substrate and pure α-Fe2O3 phase which corresponds to the rhombohedral system. The XPS analysis revealed the presence of α-Fe2O3 in the film and no tin (Sn) impurities from the FTO substrate. By changing the deposition temperature from 60 ℃ to 90 ℃, the size of particles increased; whereas, the surface morphology was not altered. The resultant films were examined as photoanode for photoelectrochemical (PEC) water splitting. The optimized electrode exhibited maximum water splitting photocurrent density of 700 μA.cm−2 at 1.6 V versus reversible hydrogen electrode (RHE) under simulated solar illumination (AM 1.5, 100 mW.cm−2) in 1 M NaOH. This could be attributed to the large electrode electrolyte interfacial area and low charge transfer resistance offered by nanorods of α-Fe2O3 of high surface-to-volume ratio.

Formation Energy of Intrinsic and Impurity Defects in Tin Dioxide

Defects in the tin dioxide determine its main characteristics, which are widely used in gas sensors. In the tin dioxide, the native and impurity defects were investigated using the density functional theory. It was shown that the oxygen vacancies dominate between the uncharged defects and the cobalt atoms occupy the places of tin atoms in the case of the cobalt doping. The found defects structures explain the contradictory experimental results obtained previously.

X-Ray Spectral Analysis of the Effect of Electronic Interaction and Electromigration on the Kinetics and Formation of the Structure of Contact Interlayers

The results are presented from investigating the effect electromigration and indium impurities in tin have on the kinetics and the formation of structures in contact interlayers in the (Sn + 3% In)–Bi system. The formation of phases in the structure of transition zones is analyzed for the first time using X-ray photoelectron spectrometry. It is found that the chemical state of components is retained at any point of the contact zone and corresponds strictly to the metallic state of the metals in contact. It is established that indium impurities and the current that flows during contact melting affect both the kinetics of the process and the formation of structures in the liquid contact interlayer, as is observed on the concentration distribution.

Изменение состояния примесных атомов -=SUP=-119m-=/SUP=-Sn в PbTe в процессе установления радиоактивного равновесия изотопов -=SUP=-119m-=/SUP=-Te/-=SUP=-119-=/SUP=-Sb

AbstractThe parameters of the emission Mössbauer spectra of PbTe using the ^119 m Sn daughter isotope with different parent nuclei ^119 mm Sn, ^119Sb, and ^119 m Te are compared. This comparison makes it possible to identify impurity tin atoms in both lead-telluride sublattices. It is found that the ratio of tin concentrations in different sublattices depends on the time after source preparation.

From stannous oxide to stannic oxide epitaxial films grown by pulsed laser deposition with a metal tin target

Stannous oxide (SnO) and stannic oxide (SnO2) are both important wide-band-gap semiconductors. To study the conductive mechanism in detail, high quality epitaxial films are essential. Here we propose a simple method to grow high quality epitaxial films of either stannous oxide or stannic oxide on an r-plane sapphire substrate by using pulsed laser deposition with a metallic tin target. The valence state of tin is controlled by tuning the oxygen pressure during the deposition procedure. Metal tin impurities and the transition phase of Sn3O4 are avoided and the growth windows from stannous oxide to stannic oxide are confirmed. For single-crystalline SnO epitaxial film, a rocking curve half-width of 0.22° is obtained, which is better than the 0.46° of that on a YSZ substrate. The minimum roughnesses achieved were 0.37 nm for the SnO2 epitaxial film and 0.84 nm for the SnO epitaxial film. The epitaxial relationship between SnO and the r-sapphire substrate was determined to be SnO [1¯10]//sapphire [1¯21¯0] and SnO [1 1 0]//sapphire [101¯1]. For SnO2, the epitaxial relation is SnO2 [0 1 0]//sapphire [1¯21¯0] and SnO2[1¯01]//sapphire [101¯1]. The band schematics, deduced by combined XPS valence band spectroscopy and optical transmittance spectroscopy, indicated p-type bands of SnO and n-type bands of SnO2. Raman spectroscopy is suggested to be a superior fingerprint of SnO single-crystalline quality, due to its greater sensitivity than X-ray diffraction.

Photosensitive center in CdTe:Sn: photorefractive, spectroscopic, and magneto-optical studies

Photorefractive properties of tin-doped CdTe crystals are studied. The material demonstrates sensitivity for low-intensity recording. A one-center model of the space-charge formation perfectly describes the experimental results. The tin impurity center is characterized using the data of optical absorption and light-induced absorption spectroscopy, pseudo-3D mapping of the photoabsorption, magnetic circular dichroism, and optical detection of magnetic resonance. Spectroscopic studies confirm appropriateness of the one-center model for describing the space-charge formation with tin as a main photorefractive center. Optical ionization (neutralization) energies are estimated for phototransitions from Sn+ (1.14 eV) and Sn0 (1.09 eV). Possible ways for improvement of the photorefractive performances are discussed.