Liquid Tin Research Articles

Physical properties of heavy liquid-metal coolants in a wide temperature range

The pulse-phase method, the gamma-attenuation method and the method of dumping oscillation of a crucible with a melt were used for measuring the velocity of sound, the density and the kinematic viscosity of a set of liquid-metal coolants for perspective nuclear reactors. There are liquid gallium, indium, tin, lead, bismuth and lead-bismuth eutectic alloy among the melts investigated. The accuracy of the measurements was as high as 0.3%, 0.2 to 0.4% and 1.5% for the ultrasound velocity, the density and the viscosity, correspondingly.

Room‐Temperature Synthesis of the Highly Polar Cluster Compound Sn[SnCl][W3Cl13

AbstractA new synthetic strategy is employed to synthesize a tungsten trinuclear cluster compound with an ionic liquid (IL) as the reaction medium. Dark brown block‐shaped crystals of Sn[SnCl][W3Cl13] were obtained at room temperature by reacting tin and WCl6 in Lewis acidic ionic liquid [BMIM]Cl/AlCl3 ([BMIM]+ = 1‐butyl‐3‐methylimidazolium). Compound Sn[SnCl][W3Cl13] crystallizes in the polar hexagonal space group P63 with cell parameters a = 959.8(1) and c = 1190.3(2) pm. The crystallographic point group of the [W3(μ3‐Cl)(μ‐Cl)3Cl9]3– cluster anions is C3, but C3v pseudosymmetry is observed within twice the standard deviation of the bond lengths. The W–W bond length is 272.18(6) pm. The tin(II) cations, which are in trigonal pyramidal and in distorted trigonal‐antiprismatic coordination spheres that comprise chloride ions, connect the clusters into layers that are stacked according to the 63 screw axis. One of the chloride ions is bound only to a single tin cation resulting in a [SnIICl]+ group with a Sn–Cl bond length of 236.1(5) pm. The pronounced polarity of the crystal structure means that its diffraction pattern exhibits huge deviations from Friedel's law. Most remarkable is that the intensity (Fc2) of reflection 004 is 175 % of the intensity of the 00$\bar {4}$ reflection.

Real-space investigation of a transverse wave in a liquid system generated by a molecular-dynamics simulation

We have invented a simple intuitive method for describing the existence of microscopic transverse wave in a liquid system produced by molecular-dynamics simulations. The method is based on an idea of using a velocity field which is determined by the velocity of atoms in liquids. One of the significant advantages of our method over a conventional method is that the waves are investigated in real space rather than in wavenumber space. This will help to visualize microscopic waves by computer graphics. We have applied the method to liquid tin at three thermodynamic states generated by ab initio molecular-dynamics simulations and found that it can distinguish whether the liquids have transverse waves or not in the same way as the conventional method. We have also shown that the velocity autocorrelation function consists of the transverse and longitudinal parts.

Reference Data for the Density and Viscosity of Liquid Copper and Liquid Tin

The available experimental data for the density and viscosity of liquid copper and tin have been critically examined with the intention of establishing a density and a viscosity standard. All experimental data have been categorized into primary and secondary data according to the quality of measurement specified by a series of criteria. The proposed standard reference correlations for the density of copper and tin are characterized by standard deviations of 1.3% and 1.0% at the 95% confidence level, respectively. The standard reference correlations for the viscosity of copper and tin are characterized by standard deviations of 6.3% and 20% at the 95% confidence level, respectively.

Thermophysical properties of liquid tin–bismuth alloys

Abstract Tin–bismuth alloys are under intense consideration as favourable lead-free solders for consumer electronics and telecommunications. The electrical and thermal conductivity, viscosity, surface tension and density were studied in a wide temperature range above the liquidus. The scaling relations have been proposed. A comparison with data available in literature is given.

Thermodynamic measurements in the Mg–Zn system

New experimental values of the enthalpies of formation of intermediate phases in the Mg–Zn system at 298 K using drop-solution calorimetry in liquid tin solvent at 665 K are presented and compared with the literature data. The heat content of MgZn 2 is also measured at high temperature in order to deduce the evolution of the enthalpy of formation.

Comparative Study of Different Indirect Laser-Based Methods Developed for Microprocessing of Transparent Materials

Micro-optics and micro-fluidics are dynamically developing research areas. However, the preparation of micro-optical elements, channels and structures is a rather complicated process. The indirect laser etching methods, i.e. the backside wet and dry etching techniques (LIBWE, LIBDE) and the plasma assisted ablation (LIPAA) developed for micromachining of transparent materials are promising techniques. In this paper our aim was to accomplish a reliable comparison of these procedures. We applied same absorber material, tin in liquid and solid states, for wet-, dryand plasma assisted etchings, respectively. The metal-fused silica interfaces were irradiated by a KrF excimer laser beam, the fluence was varied between 350 and 2000 mJ/cm. Measuring the depth of the etched holes we found that LIBWE method had the highest etch rate, while the etch rates of LIBDE and LIPAA were similar in the investigated fluence range. On the basis of the etch rate-fluence graphs we estimated the threshold values which were 340, 360 and 500 mJ/cm for wet-, dryand plasma assisted etchings, respectively. EDX analysis of the etched hole bottoms demonstrated that significant number of tin atoms were built into the surface layer of the fused silica developing a mixture layer which can play an important role in the etching processes.

Enthalpy of formation of the La–Mg intermediate phases

The aim of this work is to complete the available set of thermodynamic data on the La–Mg system in order to get reliable optimisation of this system by the CALPHAD method. Indeed the CALPHAD method requires a large set of consistent input data including both phase diagram and thermodynamic data. The enthalpies of formation of the La–Mg intermediate compounds were determined at 298 K by means of solution calorimetry in liquid Sn in a Tian–Calvet calorimeter. In these experiments, the partial enthalpies of solution of the compounds at infinite dilution in liquid tin were measured at 665 K. The enthalpies of formation of LaMg, LaMg 2 and La 2Mg 17 compounds were also calculated at 0 K by density functional theory to compare experimental and calculated values.

Enthalpy of formation of intermetallic phases from the Au–Sn system

Solution calorimetry with liquid Sn has been used for the determination of enthalpy of solution of Au and enthalpy of formation of intermetallic compounds from the Au-Sn system. Enthalpy of solution of liquid Au in liquid Sn was measured at 667 K to be −34.3 ± 0.5 kJ/g-atom and it was almost the same as cited in many earlier references. Based on the literature and this study data parabolic equations of temperature dependence of enthalpy of gold solution in liquid tin were worked out for three groups of data. Intermetallic phases were prepared and homogenized in the glow-box operated in high purity argon. They were analyzed by X-ray diffraction method before the calorimetric investigations to confirm their crystallographic structure. The obtained experimental values of enthalpy of formation were −15.3 ± 0.3, −14.2 ± 0.3 and −7.9 ± 0.6 kJ/mol of atoms for AuSn, AuSn2 and AuSn4, respectively. It was found that the obtained data in the study agreed very well with the results previously presented in literature. The observed differences were not higher than 0.5 kJ/mol of atoms. © 2009 Elsevier B.V. All rights reserved.

Effect of metal purity and testing procedure on surface tension measurements of liquid tin

The surface tension of liquid tin of three different grades of purity (99.85, 99.96, and 99.999%) was measured by the classical sessile drop method over the temperature range 523–1023 K, in heating and cooling regimes. The results obtained show that the metal purity affects the values of surface tension and its temperature dependence. The highest values of surface tension and smooth linear temperature dependence were obtained in cooling regime for tin of the highest purity. With increasing content of impurities, both surface tension and its temperature coefficient decrease while the scatter of the data increases. The surface tension values measured on heating regime show higher scatter, compared to those obtained in cooling regime, and the temperature dependence of the surface tension is curvilinear rather than linear.

Liquid Tin Anode SOFC For Direct Fuel Conversion - Impact of Coal and JP-8 Impurities

The Liquid Tin Anode solid oxide fuel cell (LTA-SOFC) has a demonstrated capability for direct fuel conversion using virtually any carbonaceous fuel. Two most notable applications under development are direct logistic fuel JP-8 conversion and direct coal (and biomass) conversion. For example a Gen 3.1 cell using logistic fuel only without fuel processing or reforming, has demonstrated specific power of 170 mW/cm2, at least 30 full thermal cycles and less than 7 minutes start up. Direct logistic fuel or coal conversion without fuel reforming/gasification/purification may also bring contaminants or impurities without fuel value in direct contact with fuel cell components. The tin anode is a fluid and a non-structural cell component so it is tolerant of many impurities. However fuel contaminants dissolved in molten tin could have a critical impact on cell components such as the electrolyte that are in direct contact with the molten tin anode. Certain fuel (V, Mo, etc.) impurities had shown causing damage to fuel cell if they were in direct contact with cell components such as electrolyte. This paper will examine liquid tin (molten tin bath) as a potential media to attenuate/reduce/eliminate harmful coal contaminants, providing a mitigation strategy for reducing a key technical risk factor of direct coal conversion using a fuel cell.

Liquid Tin Anode SOFC for Direct Fuel Conversion: Impact of Coal and Logistic Fuel Contaminants

not Available.

Hydrogen Production Using Solid Oxide Membrane Electrolyzer with Solid Carbon Reductant in Liquid Metal Anode

A laboratory-scale solid oxide membrane (SOM) steam electrolyzer that can potentially utilize the energy value of coal or any hydrocarbon reductant to produce high purity hydrogen has been fabricated and evaluated. The SOM electrolyzer consists of an oxygen-ion-conducting yttria-stabilized zirconia (YSZ) electrolyte with a Ni–YSZ cermet cathode coated on one side and liquid tin anode on the other side. Hydrogen production using the SOM electrolyzer was successfully demonstrated between 900 and by feeding a steam-rich gas to the Ni–YSZ cermet cathode and solid carbon reductant into the liquid tin anode. It was confirmed that the energy required for hydrogen production can be effectively lowered by feeding a solid carbon reductant in the liquid tin anode. A polarization model for the SOM electrolyzer was developed. The experimental data obtained under different operating conditions were curve fitted into the model to identify the various polarization losses. Based on the results of this study, work needed toward increasing the electrochemical performance of the SOM electrolyzer is discussed.

Effect of tip velocity on weld solidification process of hot-work tool steel

In order to clarify the effect of tip velocity on the weld solidification process of hot-work tool steel (SKD61) during welding, information about microstructure evolution was obtained by the combination of a liquid tin quenching and time resolved X-ray diffraction technique using intense synchrotron radiation. From the experimental results, it was found that the solidification mode was changed from FA mode (L → L+δ → L+δ+γ → L+γ → γ) to A mode (L → L+γ → γ) at high tip velocity. Moreover, the effect of tip velocity on the microstructure selection during solidification between the primary δ, ferrite and the primary γ, austenite was theoretically proven by the Kurz, Giovanola and Trivedi model. Therefore, it was understood that the solidification cracking susceptibility of hot-work tool steel (SKD61) weld metal was increased due to the δ to γ transition of the primary phase.

One-Dimensional Modeling of a Liquid Tin Anode Solid Oxide Fuel Cell

The integration of electronics into modern warfare has seen the creation of a niche market for portable power generators that run on military logistic fuel (JP-8). The 2 stage chemical/electrochemical reaction of the fuel on the anode side of the Liquid Tin Anode (LTA)-SOFC allows a range of carbonaceous fuels to be directly utilized at high efficiencies. However, the LTA-SOFC technology currently has a peak power density of 120 mW.cm-2 on JP-8. A better understanding of the anode side kinetics, thermodynamic, and transport properties would allow further optimization of this technology. A physics-based model of the LTA-SOFC was built. The model was initially developed for simple fuel before incorporation of heavy hydrocarbon fuels. This paper reports on the modeling efforts to date.

Nanometer range correlations between molecular orientations in liquids of molecules with perfect tetrahedral shape: CCl4, SiCl4, GeCl4, and SnCl4

Neutron and x-ray weighted total scattering structure factors of liquid carbon, silicon, germanium, and tin tetrachlorides, CCl(4), SiCl(4), GeCl(4), and SnCl(4), have been interpreted by means of reverse Monte Carlo modeling. For each material the two sets of diffraction data were modeled simultaneously, thus providing sets of particle coordinates that were consistent with two experimental structure factors within errors. From these particle configurations, partial radial distribution functions, as well as correlation functions characterizing mutual orientations of molecules as a function of distance between molecular centers were calculated. Via comparison with reference systems, obtained by hard sphere Monte Carlo simulations, we demonstrate that orientational correlations characterizing these liquids are much longer ranged than expected, particularly in carbon tetrachloride.

Enthalpies of formation of the La–Zn compounds between 298 K and 910 K : Experimental and theoretical investigations

The enthalpies of formation at 298 K of the eight La–Zn line phases are determined from the combination of solution enthalpies at infinite dilution obtained by the drop method in liquid tin at 665 K. For comparison, using the Density-Functional Theory, these thermodynamical growths are calculated at 0 K for the LaZn, LaZn 2, LaZn 5 and La 2Zn 17 compounds. Both based on our experimental and theoretical works and on literature data, the enthalpies of formation at 910 K of all the compounds are estimated and the heat contents between 298 K and 910 K are calculated.

Orientational correlations in molecular liquid SnI4

The total scattering structure factor of liquid tin tetraiodide (SnI(4)) has been interpreted by means of reverse Monte Carlo (RMC) modeling. From the sets of particle coordinates provided by RMC, which are consistent with experimental results within errors, partial radial distribution functions as well as correlation functions characterizing mutual orientations of molecules as a function of distance between molecular centers can be calculated. Interestingly and very much in contrast to liquids of symmetric XCl(4) molecules, the corner-to-face (or "Apollo")-type orientation of neighboring molecules has a significant (about 20%) occurrence in liquid SnI(4). Via comparison with a reference system, obtained by hard sphere Monte Carlo simulation, we demonstrate that intermolecular two-body correlations in liquid SnI(4) are determined largely by excluded volume (steric) effects; that is, intermolecular two-body interactions play only a minor role. On the other hand, as it is manifested in the large difference between the reference and "real" systems in terms of the orientational correlations, higher order interactions are indispensable. This feature can explain the extremely rich phase behavior of SnI(4) at high pressures.

Large-scale silica nanowire array grown on liquid tin and its applications as Hg (II) scavenger

Silica (SiO2) nanowire array has been prepared in large scale through thermal evaporation of SiO via oxide-assisted growth on Sn substrate. During growth the Sn substrate became a liquid, whose fluid surface induced the growth of SiO2 (from SiO disproportionation) into an aligned nanowire array on Sn surface. The liquid Sn itself further served as the solvent to dissolve elemental Si produced from SiO disproportionation. The high-density nanowire array is a type of microporous silica with a large surface area, which can serve as an efficient absorbent for scavenging heavy metal ions such as Hg (II) from water after surface modification with mercapto groups (–SH).

High precision measurements of the temperature dependence of the sound velocity in selected liquid metals

The temperature dependence of the sound velocity in liquid lead, tin, bismuth and antimony has been measured with high precision (errors of less than 0.35%) by the ultrasonic pulse transmission technique. The measurements were performed from the melting temperature to approximately 1000 °C. A smooth temperature dependence of the sound velocity was found in liquid lead and antimony. In liquid lead, a linear dependence with a negative temperature coefficient was observed whereas for liquid antimony the sound velocity displays a distinct maximum. The high precision of the measurements enabled uncovering localized features in the temperature dependence of the sound velocity in liquid tin and bismuth. The measurements provide some information on the temperature dependent structure of the molten state of these four elements.