Sn Zn Research Articles

Effect of Zn addition and Ti doping position on the diffusion reaction of internal tin Nb3Sn conductors

Addition of Zn to a Cu matrix during Cu–Zn/Sn interdiffusion reactions at 400 °C leads to the formation of a solid ternary Cu–Zn–Sn phase, β-CuZn, at the outermost reaction layer next to the porous ε phase. The use of a brass matrix considerably suppresses void formation and promotes homogeneous outward Sn diffusion in pre-annealing, prior to Nb3Sn formation. There are exactly three paths for Ti doping in the internal tin process, i.e. doping to Sn cores, Nb filaments, and Cu matrix. Ti doping to Sn cores causes a Ti-rich layer formation at the boundary of the Nb filament pack; however, no Ti-rich layers are formed as a result of small Ti doping to the matrix and to Nb filaments. The absence of Ti-rich layers is believed to contribute to a smooth Sn diffusion and suppression of void growth. Atom probe tomography measurements reveal that Ti doping to Sn cores leads to a more inhomogeneous Ti distribution near the grain boundary and a larger variation of the grain boundary thickness than doping to Nb filaments, which may contribute to a better Sn grain boundary diffusion. It is concluded that Ti doping to the matrix, instead of doping to Sn cores, might be more effective in maintaining better growth kinetics of Nb3Sn.

Effects of Al Addition on Resistive-Switching Characteristics of Solution Processed Zn-Sn-O ReRAMs.

Resistive random access memory (ReRAM) using amorphous Al-doped zinc tin oxide (a-AZTO) as resistive switching layer was fabricated by solution based deposition method. The a-AZTO films with different compositions (Al:Zn:Sn 0:1:1, 0.1:1:1 and 0.2:1:1) were prepared by solution based deposition method using low process temperature. The developed a-AZTO resistive switching nonvolatile memory devices with a Ti/Al-Zn-Sn-O (AZTO)/Pt structure exhibited typical bipolar switching behavior, remaining in a stable resistance state with exhibiting switching responses over 100 cycles, and a retention time of 10⁴ s. The resistive switching characteristics of a-AZTO ReRAMs were improved by increasing Al concentration. We demonstrate the electrical characteristics of a-AZTO TFTs are comparable to IGZO TFTs. The replacement of IGZO film with AZTO film can effectively reduce the consumption of indium (In), a toxic and rare metal, prominently reducing the production cost of transparent amorphous oxide semiconductor (TAOS) based electrical devices and improving environmental safety. Therefore, it is expected that the a-AZTO ReRAMs integrated with a-AZTO TFTs in the backplane of emerging transparent flat panel displays (FPDs) is potentially beneficial for the realization of system-on-panel (SoP) applications.

Nanobulk Thermoelectric Materials Fabricated from Chemically Synthesized Cu3Zn1-x Al x SnS5-y Nanocrystals.

Direct energy conversion of heat into electricity using thermoelectric materials is an attractive solution to help address global energy issues. Developing novel materials composed of earth-abundant and nontoxic elements will aid progress toward the goal of sustainable thermoelectric materials. In this study, we chemically synthesized Cu–Zn–Sn–S nanocrystals and fabricated a Cu3ZnSnS5–y thermoelectric material using nanocrystals as building blocks. The figure-of-merit (ZT) value of the Cu3ZnSnS5–y material was found to be 0.39 at 658 K. We substituted Zn with Al in the Cu3ZnSnS5–y system to form Cu3Zn1–xAlxSnS5–y (x = 0.25, 0.5, 0.75, and 1) to lower the lattice thermal conductivity of the resulting materials. Complete substitution of Al for Zn substantially decreased the lattice thermal conductivity and dramatically increased the electrical conductivity of the material. However, the ZT value could not be significantly enhanced, which could be primarily attributed to the high carrier thermal conductivity. These results highlight the production of Cu3Zn1–xAlxSnS5–y thermoelectric materials and unveil the scope for improvement of ZT values by altering transport properties.

Powdered composites of Al–Zn–Sn alloys for functional coatings

The features of the process of obtaining a powder composition from an alloy based on the Al–Zn– Sn system are studied. A technology has been developed for obtaining powders of optimal composition, including Al; 6–11% Zn; 6–11% Sn; 2–4% Si; 0.6–0.8% Ce. Functional wear-resistant coatings recommended for practical use in products of precision and power engineering were made by supersonic cold gas dynamic spraying.

Sequential evolution of Sn–Zn–In mineralization at the skarn-hosted Hämmerlein deposit, Erzgebirge, Germany, from fluid inclusions in ore and gangue minerals

Skarn-hosted deposits can be important high-grade resources for a variety of metals, but Sn skarns are still of subordinate importance for global mining because of their complex mineralogy and evolution. As part of recent exploration efforts, the economic potential of the Sn–Zn–In mineralization at the Hammerlein skarn-hosted deposit is currently being re-evaluated. The temporal and spatial evolution of the ore-forming hydrothermal system is still debated. We analyzed fluid inclusion assemblages (FIA) in ore and gangue minerals using conventional and infrared microthermometry and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We further estimated alteration temperatures with chlorite thermometry and compared the fluid inclusion (FI) record at Hammerlein with a mineralized greisen sample of the nearby Eibenstock granite. Cassiterite in skarn forms the major mineralization at Hammerlein during stage I and hosts FIs showing homogenization temperatures of up to 500 °C and salinities between 30 and 47 wt% NaCl eq. Cassiterite from schists and the additional greisen sample from the Eibenstock granite of the later stage II show lower homogenization temperatures (350–400 °C) and considerably lower salinities varying from 1.9 to 6 wt% NaCl eq. Despite the different homogenization temperatures and salinities, the chemical compositions of FIs hosted in both generations of cassiterite show that both (cassiterite in skarn and in schist and greisen) are similar, which points to a common source. The gangue minerals mainly contain low-temperature FIA (max. 330 °C and 2–9 wt% NaCl eq.) and are interpreted to form during further cooling of the system in stage III. Intergrown chlorite has compositions indicating similar temperatures of around 260 °C and is thus also related to stage III. FIA in sphalerite homogenize around 200 °C with salinities between 2 and 6.7 wt% NaCl eq. and show decreasing trace element contents despite having the same salinity range as the gangue minerals, indicating dilution of the ore-fluid during stage IV as a possible precipitation mechanism. Stage I inclusions are solely hosted in cassiterite from skarn, which shows the importance of fluid inclusion analyses in ore minerals, and record remarkable high mineralization temperatures, exceeding the typically temperature range reported in other studies by at least 100 °C. Our results suggest that this main ore stage is related to the early expulsion of a high-salinity brine phase from an underlying magmatic intrusion at depths greater than 3 km, which likely is a relatively short-lived event within the evolution of the hydrothermal system.

Amorphous Si–Zn–Sn–O Thin Film Transistor with In–Si–O as Transparent Conducting Electrodes

We revealed a novel method to fabricate amorphous silicon-zinc-tin-oxide (a-SZTO) thin-film transistors (TFTs) has been reported with transparent Indium–silicon–oxide (ISO) source/drain (S/D) electrodes. The presented TFTs exhibited a high field-effect mobility of 14.65 cm2/Vs, a threshold voltage of 2.87 V, and a low subthreshold swing of 0.39 V/decade. It is suggested that the small work function of ISO (4.49 eV) compared to that of a-SZTO (4.53 eV) induces an ohmic contact at the ISO/SZTO junction, which makes it possible the effective injection of electrons from oxide materials into the a-SZTO semiconductor. Determine the stability of a-SZTO TFTs under Negative bias temperature stress (NBTS) was measured ∆VTH = 1.21 V at 333 K, and − 20 V for 7200 s.

Supergravity process for enriching and separating Ag from Sn–Ag–Zn melts

The feasibility of applying supergravity technology to enhance desilverization of crude Sn with Zn was studied using the model Sn–1.5Ag–xZn alloys. The solidification characteristics of the alloys were examined using differential scanning calorimetry and scanning electron microscopy. In addition, the effect of the supergravity field on the enrichment and separation behavior of Ag in the alloy samples was investigated. Upon cooling, Ag–Zn compounds crystallized first from the alloy melts, followed by the proeutectic Sn phase and Sn–Zn eutectic phase. A greater number of Ag–Zn compounds were formed with increasing Zn content. After supergravity enrichment, the Ag–Zn compounds were concentrated at the bottom of the samples. The Ag content gradually increased along the supergravity direction, and the distribution gradient of Ag in the sample became steeper with increasing gravity coefficient (G). The Ag–Zn compounds were effectively separated from the alloy melt by filtration under supergravity fields. After separating the Sn–1.5Ag–7.5Zn alloy at 230 °C and G = 400, Ag content of molten Sn which passed through the filter was decreased by 15.6 times to 0.102 wt%, while the majority of the Ag–Zn compounds were retained by the filter, resulting in a 93.6% separation rate of Ag.

Evolution of interfacial structures and mechanical performance of sapphire and Sn–9Zn–2Al joints by ultrasound

AbstractA method of ultrasonic‐assisted soldering was applied to join sapphire with Sn–9Zn–2Al at 250°C in air. The sapphire samples were hot‐dipped in the liquid filler metal under the ultrasonic action before ultrasonic‐assisted soldering. The experimental results have shown that the joints dipped for different durations had similar morphologies, while the shear strength was dependent on the dipping duration. The shear strength of the joints increased rapidly from 13 to 22 MPa within the hot‐dipping duration of 50 seconds, and increased slowly to 46 MPa at 2000 seconds. The evolution of the interface structure and the fracture mode was analyzed. The interfacial strength was dominated by the deposited Al2O3 at the interface in the early stage. After the entire surface of sapphire was covered by deposited Al2O3, Zn‐rich phases at the interface and the thickening of deposited Al2O3 layer enhanced the interfacial strength at the later stage. Our study revealed the evolution of the interface structure and the strengthening mechanism in the joint of sapphire with Sn–Zn–Al alloys.

Enhanced optical, antibacterial and photocatalytic performance by Sn substitution in Zn0.97Mn0.03O nanostructures

Sn-doped Zn0.97Mn0.03O nanostructure was synthesized by sol–gel route. The narrow reduction of crystallite size by Sn addition is payable to the distortion induced by Sn4+ ions and the dissimilarities between ionic radius of Zn2+ and Sn4+ ions. Surface-morphology is significantly tuned towards spherical shape by Sn-doping which is confirmed by both SEM and TEM. Widening of band gap with Sn addition can be explained by Burstein–Moss effect through energy level diagram. The enhanced PL emission is demonstrated by the poor crystallinity and induced high concentration of defects by Sn addition. The combined effect of reduced size and generation of reactive oxygen species (ROS) made higher antibacterial efficiency in Zn–Mn–O doped with Sn system. Sn, Mn dual doped ZnO nanostructures are identified as the efficient catalyst for the degradation of methyl orange dye than the other samples. The addition of Sn in Zn–Mn–O nanostructures might enhance the specific surface area by lowering the particle size which might contribute to high dye degradation. In the current studies, Sn doping Zn0.97Mn0.03O is identified as multifunctional materials.

Effect of Elemental Coating of Sn or Zn by Magnetron Sputtering on Corrosion and Wear Resistance of Interstitial-Free Steel

This investigation aims to enhance both wear and corrosion resistance of interstitial-free (IF) steel through deposition of pre-determined thickness of pure Sn or Zn or alternate elemental Sn–Zn layers by twin-target magnetron sputtering at desired deposition rate. The thickness, average grain size, hardness and resistance to wear and corrosion of the deposit depend on the deposition parameters. Deposition of either Sn or Zn from single target seems more effective than that from twin target in improving these tribo-corrosion properties of IF steel. The results indicate that sputter deposition of Sn or Zn offers a superior wear and corrosion resistance to galvanized steel and can be a potential route to replace the conventional practice of hot dip galvanizing for the said objective.

Effects of aluminum addition (x = 0–1 wt%) on the thermal behavior, microstructure and mechanical properties of Zn–30Sn high temperature lead-free solder alloy

The thermal behavior, microstructure and mechanical properties of the modified lead-free Zn–30Sn–xAl (x = 0, 0.1, 0.5, 1.0 wt%) composite solder alloys had been investigated in the present study. Addition of Al tended to refine the microstructure and decrease the melting point. The analysis of microstructure showed that the supersaturated precipitation of Al (0.5 wt%) in η-Zn phase would result in the formation of Zn–Al phase. Due to the peritectic reaction, the Zn–Sn–Al phase was observed when the Al content was 1 wt%. The refinement of eutectic structure and η-Zn phase improved the elongation when the minor Al element (0.1 and 0.5 wt%) was added into Zn–30Sn solder. However, when the Al content was 1.0 wt%, the elongation of Zn–30Sn-based solder decreased because of the stress concentration. Besides, the ultimate tensile strength (UTS) of the alloy increased from 45.48 to 91.26 MPa, and the yield strength increased from 35.26 to 37.53 MPa. The analysis of the fractography showed that the brittle fracture gradually turned into mixed fracture mode of ductile fracture and ductile fracture with the increasing content of Al.

Microstructure and mechanical property of high strength Mg–Sn–Zn–Al alloys

ABSTRACTThis paper aims to reveal the microstructure and mechanical properties of as-cast and hot-rolled Mg–Sn–Zn–Al based alloys. Three alloys, Mg–5Sn–2Zn (TZ52), Mg–5Sn–2Zn–2Al (TAZ522) and Mg–5Sn–5Al–1Zn–0.2Mn (TAZM5510) alloys were studied. The results revealed that the as-cast alloys showed fine dendritic structures. The TAZM5510 alloys exhibited moderate yield strength of 98 MPa with good elongation of ∼15%, which was comparable to several commercially used Mg die-castings. Mechanical properties were significantly improved after multi-pass rolling. The TZ52 sheet showed a high yield strength of 277 MPa with excellent ductility exceeding 30%, and the TAZM5510 sheet exhibited the highest tensile strength of 386 MPa while keeping desirable elongation of 16.6%. These sheets are termed as strong and ductile Mg–Sn–Zn–Al wrought alloys.

Improved phase-change properties of Sn–Zn–Sb alloys with a two-step crystallization process for multi-level data storage applications

Abstract We investigated Te-free ZnSb films for the potential applications in multi-level data storage. It was found that, the films could exhibit three phases during crystallization process, e.g., high amorphous phase, intermediate metastable ZnSb phase, and low stable ZnSb phase. However, the formation of the voids in the metastable ZnSb phase, high crystallization temperature and large amorphous resistance have an influence on the structure stability and SET power consumption during the repeated switching process. Interestingly, doping of Sn with a concentration of 11.1 at% into ZnSb can prevent the growth of metastable ZnSb grains, and different crystals like SnSb and ZnSnSb2 can be precipitated out during heat treatment, but the two-step crystallization process is kept unchanged. Moreover, the chemical environment of Sn in Zn–Sb studied by X-ray photoelectron spectroscopy indicates the formation of the large number of Sn–Sb and Sn–Zn bonds, which in turn reduces the crystallization temperature, lowers crystallization activation energy as well as decreases the amorphous resistance. The in situ transmission electron microscopy measurements on the optimized (ZnSb)88.9Sn11.1 composition confirms a two-step phase transition process from amorphous to rhombohedral SnSb crystals first, and then to the stable tetragonal ZnSb2Sn crystals. These excellent properties make Zn–Sb–Sn materials useful as a phase-change layer in low-power and high-density memory.

Theory and technology for electroplating a rose golden Cu–Zn–Sn alloy using a disodium ethylenediamine tetraacetate system

A non-cyanide rose golden electroplating system was investigated in this work. The electroplated layer of Cu–Zn–Sn alloy was also investigated using a disodium ethylenediamine tetraacetate (EDTA·2Na) system, in which CuSO4·5H2O, ZnSO4·7H2O and Na2SnO3·3H2O were the main salts. EDTA·2Na acted as a complexing agent. Finally, NaOH acted as a buffering agent in the electroplating solution. The effects of different electroplating solutions on colour, micro-topography, composition and phase structure of the electroplated layer was analysed by photo analysis, SEM, EDS and XRD. Meanwhile, different electroplating solutions were analysed and compared by electrochemical analysis and UV–Vis, FTIR and NMR spectroscopy. A rose golden electroplated layer of Cu–Zn–Sn alloy could be obtained by adjusting the amount of the main salts. The composition of the electroplated layer was 98.81% Cu, 0.77% Zn and 0.42% Sn. Moreover, the electroplated layer was composed of regular 50–100 nm particles. The composition of the ternary alloy-electroplated layer was Cu, Cu5Zn8 and Cu10Sn3 phase. At the same time, the cathode only had a single deposition peak at − 1.22 V by electrochemical analysis of the electroplating solution. UV, IR and NMR analyses show that a chelate was formed with EDTA·2Na and metal ions in an alkaline environment. These results may provide a theoretical guidance for a new technology for Cu–Zn–Sn alloy electrodeposition.

Macrostructure and Strength of the Al–Zn–Sn Composite Produced by Liquid-Phase Sintering of the Al–Zn Alloy and Pure Tin Powder Mixture

Features of liquid-phase sintering compacts made of powders of the Al–10Zn alloy and tin of the PO 2 brand, as well as the influence of sintering modes on the structure and strength of forming antifriction composite of the (Al–10Zn)–40Sn composition, are studied. The porosity of the initial green compacts varies in a range of 5–18%. Compacts are sintered in a vacuum furnace under a residual gas pressure no higher than 10–2 MPa. The sintering temperature varies in a range of 550–615°C and corresponds to the partial wetting of aluminum with liquid tin. The sample holding time at a specified temperature is from 30 to 180 min. Structural studies show that the particle size of the aluminum and tin phases increases with an increase in the sintering temperature and holding time. The mechanical properties of sintered composites are determined by their compression testing. The samples are cut from the middle of sintered compacts. It is established that samples made of the (Al–10Zn)–40Sn sintered alloy possess high ductility and exhibit higher strength when compared with the Al–40Sn sintered composite with a pure aluminum matrix due to the more intense strain hardening of a matrix at a high deformation. It is found that sintered composites prepared from high-density green compacts subjected to preliminary low-temperature holding possess the highest strength. Based on the results, it is concluded that the liquid-phase sintering in a specified temperature range makes it possible to prepare (Al–10Zn)–40Sn composites with a bound aluminum matrix effectively preventing the strain localization in soft tin-based phase interlayers. The optimal sintering temperature should not exceed 600°C.

Effects of Zn on intermetallic compounds and strength of Al/Mg joints ultrasonically soldered in air

Dissimilar Al/Mg alloys were soldered by changing the Zn content in Sn-based solders with the assistance of ultrasonic. Results showed that the Al/Mg intermetallic compounds (IMCs) of Al3Mg2 and Al12Mg17 were avoided, but a new IMC of Mg2Sn formed in the joints. Mg2Sn was blocky inside the joints and continuous near the Mg side. Blocky Mg2Sn did not present a connection to the continuous Mg2Sn in joints soldered by Sn–16Zn. The shear strength of the joints increased with the addition of Zn into the solders. The maximum shear strength of 49 MPa was obtained when the Sn–16Zn solder was used. The Al content exceeded its ultimate solution in the solder and increased with increasing Zn. The floating of Al grains was observed in the joints soldered by Sn, Sn–3Zn, and Sn–9Zn because of sound radiation pressure, which was blocked by Zn grains in the joint soldered by Sn–16Zn.

Synthesis and characterization of heterobimetallic SnIV–CuII/ZnII complexes: DFT studies, cleavage potential and cytotoxic activity

Heterobimetallic complexes [Cu(L)Sn(CH3)2(H2O)(Cl)] (3) and [Zn(L)Sn(CH3)2(H2O)(Cl)] (4) have been synthesized from their monometallic analogs [Cu(L)(H2O)(Cl)] (1) and [Zn(L)(H2O)(Cl)] (2) of Schiff base ligand (L) which were characterized by various spectroscopic and analytical methods. DFT calculations were carried out to simulate the vibrational spectra to support the anticipated structures. The interaction studies of ligand (L) and complexes (1–4) with CT–DNA were performed by employing UV–vis, and fluorescence spectroscopic techniques which revealed that heterobimetallic complexes 3 and 4 showed higher affinity with DNA due to dual mode of action as compared to monometallic complexes 1 and 2. Further, validation of the interaction studies was accomplished by carrying out molecular docking studies with DNA. Gel assay displayed that both the complexes have ability to cleave DNA efficiently and are specific minor groove binders. CuII–SnIV complex 3 cleaved pBR322 DNA via oxidative mechanism, while ZnII–SnIV complex 4 followed hydrolytic cleavage pathway. In vitro cytotoxicity evaluation of complex 3 was tested on a different cancer cell lines showing promising antitumor activity.Communicated by Ramaswamy H. Sarma

Effect of the Active Channel Thickness Variation in Amorphous In-Zn-Sn-O Thin Film Transistor.

Ternary oxide thin films in the In₂O₃-ZnO-SnO₂ system were studied for potential applications in oxide semiconductor thin film transistors (TFTs). An amorphous In-Zn-Sn-O (a-IZTO) active channel layer was deposited by RF magnetron sputtering at room temperature on an n++ Si substrate. Films from a sintered ceramic target with a nominal chemical composition of In:Zn:Sn = 40:50:10 at.% were prepared with thicknesses ranging from 15 nm to 150 nm, which was followed by annealing at 350 °C for 30 minutes in air. Subsequently, a bilayer Cu/Ti metal contact was deposited as the source/drain electrodes on the top surface through a shadow mask using an e-beam evaporator. The thickness of the active channel layer greatly influenced the characteristics of the oxide thin film transistors. The best transistor characteristics were observed from the test device with a channel thickness of 30 nm and a high on/off current ratio of approximately 108, high field effect mobility of 25 cm²/Vs, low threshold voltage of -0.1 V, and very small subthreshold swing of 0.14 V/dec.

Investigation of the surface of Ga⁻Sn⁻Zn eutectic alloy by the characterisation of oxide nanofilms obtained by the touch-printing method.

Ga–Sn–Zn eutectic alloy is a non-toxic liquid metal alloy which could be used in a multitude of applications, including as a heat transfer agent, in gas sensing, and in medicine. Alloys containing gallium readily oxidise in air, forming a thin oxide layer that influences the properties of liquid metals and which has not been studied. In this study, the oxide layer formed on Ga–Sn–Zn alloy was transferred at room temperature onto three substrates—quartz, glass and silicon. The contact angle between the liquid alloy and different substrates was determined. The obtained thin oxide films were characterised using atomic force microscopy, X-ray photon spectroscopy, and optical and transmission electron microscopy. The contact angle does not influence the deposition of the layers. It was determined that it is possible to obtain nanometric oxide layers of a few micrometres in size. The chemical composition was determined by XPS and EDS independently, and showed that the oxide layer contains about 90 atom % of gallium with some additions of tin and zinc. The oxides obtained from the eutectic Ga–Sn–Zn liquid alloys appear to be nanocrystalline.

Microstructure, mechanical properties, and drop reliability of CeO2 reinforced Sn–9Zn composite for low temperature soldering

In this study, CeO2 reinforced eutectic Sn–9Zn–xCeO2 composite specimens were prepared by mixing and melting route. The CeO2 nanoparticles were synthesized by chemical precipitation method. The composite samples were produced by adding CeO2 nanoparticles from, x = 0, 0.3, 0.6 to 0.9 wt% in the eutectic Sn–9Zn matrix. The microstructural analysis revealed that the presence of CeO2 in Sn–9Zn–xCeO2 matrix refined the Zn needles when CeO2 was added up to x = 0.6. The wetting properties of these solders were considerably enhanced (≈17%) over monolithic Sn–9Zn alloy. The melting properties of Sn–9Zn–xCeO2 solders showed a narrow pasty range 3.9 °C–7.6 °C. The mechanical strength and ductility of the solders were also improved after addition of CeO2 nanoparticles in the matrix up to x = 0.6. An optimum fraction of 0.6 wt% CeO2 in eutectic Sn–9Zn alloy is recommended to obtain a set of enhanced wetting, strength and drop reliability of Sn–9Zn solder.