Tin Impurity Research Articles

Effect of B, N, Ge, Sn, K doping on electronic-transport properties of (5, 0) zigzag carbon nanotube

In this paper the effect of impurity on the electronic properties and quantum conductance of zigzag (5, 0) carbon nanotube have been studied by using the Density Functional Theory (DFT) combined with Non-Equilibrium Green’s Function (NEGF) formalism with TranSIESTA software. The effect of Boron (B), Nitrogen (N), Germanium (Ge), Tin (Sn) and Potassium (K) impurities on the CNT conduction behavior and physical characteristics, like density of states (DOS), band structure, transmission coefficients and quantum conductance was considered and discussed simultaneously. The current−voltage (I−V) curves of all the proposed models were studied for comparative study under low-bias conditions. The distinct changes in conductance reported as the positions, number and type of dopants was varied in central region of the CNT between two electrodes at different bias voltages. This suggested conductance enhancement mechanism for the charge transport in the doped CNT at different positions is important for the design of CNT based nanoelectronic devices. The results show that Germanium, Tin and Potassium dopant atoms has increased the conductance of the model manifold than other doping atoms furthermore 10 Boron and 10 Nitrogen dopant atoms showed the amazing property of Negative Differential Resistance (NDR).

Equilibrium geometries, electronic structure and magnetic properties of ConSn (n = 1–12) clusters from density functional calculations

Equilibrium geometries, relative stabilities, electronic stabilities and magnetic properties of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters have been systematically investigated by using relativistic all-electron density functional theory with generalized gradient approximation. The results indicated that the lowest-energy structures of Co[Formula: see text]Sn ([Formula: see text] = 1–5, 7, 9 and 10) clusters are similar to those of corresponding Co[Formula: see text] clusters. As for Co6Sn, Co8Sn, Co[Formula: see text]Sn and Co[Formula: see text]Sn clusters, the most stable structures give rise to a geometry reconstruction. In the low-lying structures of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters, tin impurity prefers to occupy the external site. The second-order difference energy of the ground-state Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters shows a pronounced odd–even oscillation with the number of Co atoms, and the clusters exhibit higher stability at [Formula: see text] = 5. Compared with corresponding pure Co[Formula: see text] clusters, the total magnetic moment of the Co[Formula: see text]Sn clusters reduces with 1, 3 and 5 [Formula: see text], respectively. The different magnetic changes of the tin doped Co clusters are analyzed in detail based on the magnetism coupling, density of state and hybridization between cobalt and tin atoms.

Reaction synthesis of the Ti2AlN MAX-phase

The Ti2AlN MAX-phase is synthesized by reaction sintering from Ti–AlN powder mixtures. The optimal synthesis mode of the compound containing less than 1% of the TiN impurity phase is established. It includes isothermal annealing at 1300°C for 2 h in argon at a pressure of 3 atm. The influence of the preliminary mechanical activation of the powder mixture and the reaction synthesis medium on the yield of the Ti2AlN phase are investigated. It is shown that the activation leads to an increase in the content of the secondary TiN phase. It is revealed that the vacuum synthesis also does not make it possible to form the singlephase Ti2AlN material.

Effect of rare earth cerium and impurity tin on the hot ductility of a Cr-Mo low alloy steel

The specimens of 1Cr-0.5Mo low alloy steel, undoped, Sn-doped and Ce+Sn-doped, were austenitized at 1300 °C and then cooled down to different temperatures in the range of 700–1050 °C, followed by tensile tests with the aid of a Gleeble machine. The reduction of area (RA) obtained from the test was employed to evaluate the hot ductility of the steel. The tested specimens were characterized using different techniques. Minor Sn could considerably reduce the RA values of the steel in the whole temperature range, and the hot ductility curve could be widened and deepened. Nevertheless, minor Ce could improve the hot ductility of the Ce+Sn-doped steel by fully suppressing the Sn-induced hot ductility deterioration. FEGSTEM microanalysis showed that the Sn or Ce and Sn atoms segregated to austenite grain boundaries in the Sn-doped or Ce+Sn doped specimens. The detrimental effect of Sn on the hot ductility could be attributed mainly to the segregation of Sn as it could decrease the grain boundary cohesion and in turn enhanced the grain boundary sliding and cracking. However, this detrimental effect of Sn could be counteracted by the segregation of Ce which could increase the grain boundary cohesion and in turn restrained the grain boundary sliding and cracking. Accordingly, a minor addition of rare earth Ce could be an effective method of suppressing the detrimental effect of impurity elements on the hot ductility of a Cr-Mo low alloy steel.

Electron exchange between tin impurity U – centers in PbS z Se1–z alloys

Using emission 119mmSn(119mSn) and 119Sb(119mSn) Mossbauer spectroscopy, it is shown that impurity tin atoms in PbSzSe1–z alloys substitute lead atoms and are two-electron donors with negative correlation energy (U– centers). It is found that the energy levels related to impurity tin atoms are in the lower half of the band gap at z ≥ 0.5 against the background of allowed valence-band states at z ≤ 0.4. The electron exchange between neutral and doubly ionized tin U– centers in partially compensated Pb0.99Sn0.005Na0.005SzSe1–z alloys is studied. The activation energy of this process decreases from 0.111(5) eV for a composition with z = 1 to 0.049(5) eV for compositions with c ≤ 0. For all z, the exchange is implemented via the simultaneous transfer of two electrons using delocalized valence-band states.

On the tin impurity in the thermoelectric compound ZnSb: Charge-carrier generation and compensation

The technique for measuring the Hall coefficient and electrical conductivity in the thermal cycling mode is used to study the effect of the Sn impurity on the microstructure and properties of pressed ZnSb samples. Tin was introduced as an excess component (0.1 and 0.2 at %) and as a substitutional impurity for Zn and Sb atoms in a concentration of (2–2.5) at % The temperature dependences of the parameters of lightly doped samples are fundamentally like similar curves for ZnSb with 0.1 at % of Cu. The highest Hall concentration, 1.4 × 1019 cm–3 at 300 K, is obtained upon the introduction of 0.1 at % of Sn; the dimensionless thermoelectric figure of merit attains its maximum value of 0.85 at 660 K. The experimental data are discussed under the assumption of two doping mechanisms, which are effective in different temperature ranges, with zinc vacancies playing the decisive role of acceptor centers. In two ZnSb samples with SnSb and ZnSn additives, the charge-carrier compensation effect is observed; this effect depends on temperature and markedly changes with doping type. As in p-type AIV–BVI materials with a low Sn content, hole compensation can be attributed to atomic recharging Sn2+ → Sn4+. Types of compensating complexes are considered.

Reaction synthesis of Ti2AlN MAX-phase

Ti2AlN MAX-phase was synthesized from the powder mixtures of Ti–AlN using the reactionary sintering method. The optimal synthesis mode for the compound containing less than 1 % of TiN impurity phase was determined: isothermal annealing at 1300 °C for 2 hours in argon at a pressure of 3 atm. The preliminary mechanical activation and the reaction synthesis environment were investigated as the factors that can influence the yield of the Ti2AlN phase. It is shown that the activation increases the level of TiN secondary phase. It was also found that the vacuum synthesis does not enable obtaining of single-phase Ti2AlN.

Single-pulse laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass for pulse widths of 500 fs, 10 ps, 20 ns.

In this work, we report a comparative study of the laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass as a function of the pulse width and for IR laser wavelengths. We determine the ablation threshold for three different pulse durations: τ=500 fs, 10 ps, and 20 ns. Experiments have been performed using a single laser pulse per shot in an ambient (air) environment. The results show a significant difference, of two orders of magnitude, between the group of ablation thresholds obtained for femtosecond, picosecond, and nanosecond pulses. This difference is reduced to 1 order of magnitude in the soda-lime substrate with tin impurities, pointing out the importance of the incubation effect. The morphology of the marks generated over the different glass materials by one single pulse of different pulse durations has been analyzed using a scanning electron microscope (FESEM ULTRA Plus). Our results are important for practical purposes, providing the ablation threshold data of four commonly used substrates at three different pulse durations in the infrared regime (1030-1064 nm) and complete data for increasing the understanding of the differences in the mechanism's leading ablation in the nanosecond, picosecond, and femtosecond regimes.

Broad spectral response photodetector based on individual tin-doped CdS nanowire

High purity and tin-doped 1D CdS micro/nano-structures were synthesized by a convenient thermal evaporation method. SEM, EDS, XRD and TEM were used to examine the morphology, composition, phase structure and crystallinity of as-prepared samples. Raman spectrum was used to confirm tin doped into CdS effectively. The effect of impurity on the photoresponse properties of photodetectors made from these as-prepared pure and tin-doped CdS micro/nano-structures under excitation of light with different wavelength was investigated. Various photoconductive parameters such as responsivity, external quantum efficiency, response time and stability were analyzed to evaluate the advantage of doped nanowires and the feasibility for photodetector application. Comparison with pure CdS nanobelt, the tin-doped CdS nanowires response to broader spectral range while keep the excellect photoconductive parameters. Both trapped state induced by tin impurity and optical whispering gallery mode microcavity effect in the doped CdS nanowires contribute to the broader spectral response. The micro-photoluminescence was used to confirm the whispering gallery mode effect and deep trapped state in the doped CdS nanowires.

Impurity tin atoms in glassy As x S1 − x and As x Se1 − x

119Sn Mossbauer emission spectroscopy data demonstrate that the impurity tin atoms resulting from the radioactive decay of the 119Sb isotope in the structure of glassy AsxS1 − x and AsxSe1 − x alloys reside on the arsenic site and act as two-electron amphoteric centers with a negative correlation energy: tetravalent six-coordinate tin acts as a singly ionized donor, and divalent three-coordinate tin, as a singly ionized acceptor.

Fluence ablation threshold dependence on tin impurities in commercial soda-lime glass.

In this paper, we study the reduction in the fluence ablation threshold induced by tin impurities incorporated in float soda-lime glass during the fabrication process. The laser system used in the experiments was a Nd:YVO4 laser operating at 1064 nm with a pulse duration of 20 ns. The fluence ablation thresholds found were 112 J/cm2 for the tin side and 920 J/cm2 for the tin-free side, which means a reduction of nearly 1 order of magnitude. The fluence ablation threshold reduction permits the manufacturing of narrower grooves with small level of roughness, obtaining quality elements in low-cost soda-lime substrates.

Effect of Impurity Tin on the Creep Properties of a P91 Heat-Resistant Steel

The creep properties of P91 steel specimens undoped and doped with 0.058 wt pct tin, which was normalized from 1328 K (1055 °C) and tempered at 1033 K (760 °C), were examined under different engineering stresses (150 to 210 MPa) and temperatures [873 K to 923 K (600 °C to 650 °C)]. The creep behavior followed the temperature-compensated power law and Monkman–Grant equations. In the temperature-compensated power law equation, the apparent activation energy and stress exponent for creep were approximately 541 kJ/mol and 12 for the undoped steel and 527 kJ/mol and 11 for the Sn-doped one, respectively. In the Monkman–Grant relation, the values of constants m and C were around 1.062 and 0.0672 for the undoped steel, and 1.012 and 0.0650 for the Sn-doped one, respectively. The 100 MPa stress creep lifetime at 873 K (600 °C) was estimated as 100641 hours for the undoped steel and 35290 hours for the Sn-doped steel, respectively. These indicated that Sn substantially deteriorated the creep properties of the steel. It was found that grain or subgrain boundary segregation of Sn could promote the nucleation of cavities or microcracks, thereby leading to the deterioration of the steel creep properties.

Effect of the tin impurity on the energy spectrum and photoelectric properties of nanostructured In2O3 films

It is shown that the doping of colloidal indium-oxide nanocrystals with tin shifts the absorption edge to shorter wavelengths of the visible spectral region and induces considerable absorption in the infrared region. The shape of the absorption and transmittance spectra in the infrared region is characteristic of the local surface plasmon resonance. According to estimations, the concentration of free charge carriers in In2O3(Sn) reaches 1019 cm−3. The temperature dependences of the photoconductivity in the range 77–300 K are indicative of hopping conduction in nanostructured films based on In2O3(Sn) nanocrystals. The mechanisms responsible for the effect are discussed.

Determination of the composition of multicomponent chalcogenide semiconductors by X-ray fluorescence analysis

The composition of Asx(GeySe1 − y)1 − x glassy alloys is quantitatively determined by measuring the X-ray fluorescence spectrum of a Ge0.2As0.4Se0.4 reference alloy. The atomic fractions of arsenic, germanium, and selenium are calculated from the X-ray fluorescence spectra and the xRFA = f(x) and yRFA = f(y) dependences are plotted. These dependences make it possible to determine the composition of the glasses with an accuracy of ±0.0005 for x and y. This procedure is effective for finding the concentration of the tin impurity in Pb1 − xSnxSe crystalline solid solutions. However, it is impossible to determine the content of tellurium in Tex(AsySe1 − y)1 − x glassy alloys because the alloy components have significantly different X-ray fluorescence characteristics.

Effect of tin on the processes of silicon-nanocrystal formation in amorphous SiO x thin-film matrices

The effect of tin on the processes of silicon-nanocrystal formation in amorphous silicon oxide (a-SiO x , x ≈ 1.15) thin-film matrices is studied. It is established that the tin impurity accelerates the processes of crystallization of amorphous silicon. After heat treatment in an argon atmosphere, silicon crystallites embedded in the tin-containing silicon oxide (a-SiO x Sn) matrix are smaller in size (6–9 nm) compared to crystallites in a-SiO x (≥10 nm). It is shown that, upon annealing of a-SiO x Sn at temperatures increased from 800 to 1100°C, the volume fraction of the crystalline phase increases from 20 to 80%. At the same time, in the samples free from tin, the silicon crystalline phase appears only upon annealing at 1000°C and 1100°C, and the volume fraction of the crystalline phase is 45 and 65%, respectively.

Поведінка водню при кристалізації тонких плівок кремнію, легованих оловом

The behavior of a hydrogen impurity in the course of crystallization of thin silicon films doped with tin (a-SiSn films) has been studied. It is found that the band located at about 2000–2200 cm^−1 and corresponding to the IR absorption at silicon–hydrogen bonds is absent from the spectra of as-deposited (at a temperature of 300 ◦C) a-SiSn films with Sn contents within the interval of 1–10 at.%. In undoped thin silicon films (a-Si films), the hydrogen content diminishes below the sensitivity threshold of the measurement technique only after the annealing of the specimens at 700 ◦C. The absence of hydrogen in a-SiSn films is in good agreement with the results of EPR studies and the results of Raman scattering studies of structural transformations in thermally treated films. It is shown that the formation of crystalline phases in a-SiSn occurs at lower temperatures as compared to those in a-Si, with a correlation taking place between the crystallization temperature for Si clusters and the concentration of the tin impurity. Taking into account that tin reduces the temperature of the hydrogen effusion from the film volume and, accordingly, stimulates the ordering in the specimen structure, it is possible to consider that hydrogen impurity takes part in the processes that result in a decrease of the crystallization temperature for a-SiSn.

Precision affinage of copper from crow-bar and wastes

The model of the deep copper refining from the secondary raw materials using methods of physical and chemical analysis was considered. The theoretical and experimental results of copper refining from the secondary raw materials using phosphide Cu3P were proposed. The copper phosphide Cu3P was added into melting during fire refining. The copper phosphide Cu3P influence on the refining level was estimated on the tin, lead, zink and antimony impurities. Reactions analysis showed that the Cu3P addition helps to form stable oxidiger P2O5 and copper oxides recoverability. It was determined that the reaction, of conversion the remaining impurities into slag place at the first stage by P2O5 formation and was followed by phosphates of lead, zinc and tin impurities formation. Keywords: melting, fusion, five refining, impurities, copper phosphide Cu3P.

Mikrostruktura tonkykh kompozytnykh plivok Si−Sn

Microstructure investigations of thin Si-Sn alloy films were carried out, by using Auger and Raman spectroscopies, X-ray fluorescence analysis, and electron microscopy. The films were produced by the thermal-vacuum coevaporation of Si and Sn. The properties of films with the Sn content ranging from 1 to 5 wt.% are studied. A significant influence of the tin impurity on the formation of a film surface microrelief and nanocrystals in the amorphous matrix is found. The size of quasispherical formations on the film surface can be of the order of 100 nm. The volume fraction of the silicon nanocrystalline phase in a film can reach 90%. The roles of fabrication conditions and growth rate on the distributions of Sn and technological impurities C and O over the film surface and across the film thickness are analyzed.

Ti<sub>2</sub>AlN Prepared by Self-Propagating High-Temperature Combustion Method Using TiN as Additive

Ti2AlN ceramic have been prepared by self-propagating high-temperature synthesis method using Ti, Al and TiN mixture as raw materials under different N2 pressures. X-ray diffraction (XRD) and scanning electron microscope (SEM) have been used to determine the phase composition and micro morphology of the products. XRD analysis indicates that the main phase of the products is layered ternary compound Ti2AlN, but there are TiN and AlTi3 impurities in the products. With increasing N2 pressure, the relative content of TiN and AlTi3 decreases. SEM imagines exhibits that the grains of the products become larger with increasing N2 pressures.

Effect of N<sub>2</sub> Pressure on the Phase Composition and Morphology of Ti<sub>2</sub>AlN Prepared by Self-Propagating Combustion Method

Ti2AlN ceramic have been prepared by self-propagating high-temperature synthesis method using Ti, Al and TiAl mixture as raw materials under different N2 pressures. X-ray diffraction (XRD) and scanning electron microscope (SEM) have been used to determine the phase composition and micro morphology of the products. XRD analysis indicates that the main phase of the products is layered ternary compound Ti2AlN, but there are TiN and AlTi3 impurities in the products. With increasing N2 pressure, the relative content of TiN increases, whereas the relative content of AlTi3 decreases. SEM imagines exhibits that layered grains of the products become larger and tighter with increasing N2 pressures.