Ga Sn Research Articles

Experimental and numerical analysis of free surface deformation in an electrically driven flow

The present paper presents the experimental and numerical results of an electrically induced flow in a cylindrical container (188mm diameter) filled with a In–Ga–Sn alloy. The electric current is applied from copper electrodes of various diameters (4–8mm) and varied from 100 to 700A. The deformation of the free surface just under the electrode is reported in term of depth. At some critical current an arc develops around the electrode tip. To explore numerically what happens in such flows, calculations of the Magnetohydrodynamic (MHD) flow are performed. The numerical model is based on a potential formulation for the electromagnetic field. The evolution of the free surface flow is tracked with a VOF model. The electromagnetic parameters are fully coupled with the evolution of the free surface and the contact surface at the electrode. At low current density the interface is shifted downward by the pinch action of the Lorentz force. In the same time the rotational part of the Lorentz force drives the liquid metal flow in radial direction towards the electrode. The flow is accelerated towards the electrode and sinks in the form of a strong jet. At the high current density, the velocities are strong enough to induce further displacement of the interface by a Bernoulli mechanism. The combined action of the pinch and the rotational components of the Lorentz force on the interface displacement, scales as I2. The numerical and experimental results are in good agreements.

Sn–Ga co-doped ZnO nanobelts fabricated by thermal evaporation and application to ethanol gas sensors

ZnO nanobelts doped with SnO2 and Ga2O3 were synthesized in large scale using a thermal evoparation method without any catalyst. It was demonstrated that obvious contrasts were presented between the backbone and double rough edges. On the basis of HRTEM, numerous nanodots of diameter 5nm deposited randomly on the backbone surfaces. They were grown with the same orientation along [0001] direction. Gas sensitivity experiments on Sn–Ga codoped ZnO nanobelts were carried out at different temperatures. The results indicated a good response toward 400ppm ethanol which was as high as 31.033 at the operating temperature of 225°C.

Ab-initio study of the stability of the D8m-Nb5Sn2Ga and D8m-Ta5SnGa2 compounds

First principles calculations have been performed in the T–Sn–Ga (T=V, Nb, Ta) systems along the section xT=0.625. The enthalpies of formation of the binary and ternary D8m, D81, and D88 structures have been calculated. In the V–Sn–Ga system, no ternary structure is stable in the section. In the Nb–Sn–Ga system, the ternary compound D8m-Nb5Sn2Ga is stable. In the Ta–Sn–Ga system, a combination of the ab-initio calculations and Gibbs energy calculations using the sublattice model allows the show that the phase D8m-Ta5(Sn,Ga)2Ga with a mixed occupancy of the 8h sites of the structure by Ga and Sn atoms is stable at high temperature due to the configurational entropy. These results are in agreement with the experimental determinations previously published in the literature.

On the Cu–Ga system: Electromotive force measurement and thermodynamic reoptimization

The Cu–Sn–Ga system seems to be a promising lead free solder due to properties of gallium: excellent wetting and decreasing melting temperature of Cu–Sn lead-free solder. A new experimental measurement in a solid phase as well as a new thermodynamic description of this system is presented in this work. A good agreement between calculation and available experimental data was found.

Anodic activation of aluminium containing small amounts of gallium and tin

Anodic activation due to surface enrichment of Sn and Ga on AlGaSn model alloys, containing 50–1000ppm Sn and 1000ppm Ga in pure aluminium, as a result of heat treatment was investigated. Sn was enriched because of annealing at 300°C, while Ga was stable in solid solution because of its high solubility in Al. Anodic polarization in 5% NaCl solution resulted in highly active surfaces in relation to the binary alloys AlGa and AlSn. Presence of segregated Sn at the surface catalysed dealloying, such that Ga was enriched on the corroding surface giving increased activation.

Distribution of chemical elements in soils and stream sediments in the area of abandoned Sb–As–Tl Allchar mine, Republic of Macedonia

The aim of this study was to investigate the distribution of some toxic elements in topsoil and subsoil, focusing on the identification of natural and anthropogenic element sources in the small region of rare As–Sb–Tl mineralization outcrop and abandoned mine Allchar known for the highest natural concentration of Tl in soil worldwide. The samples of soil and sediments after total digestion were analyzed by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–atomic emission spectrometry (ICP–AES). Factor analysis (FA) was used to identify and characterize element associations. Six associations of elements were determined by the method of multivariate statistics: Rb–Ta–K–Nb–Ga–Sn–Ba–Bi–Li–Be–(La–Eu)–Hf–Zr–Zn–In–Pd–Ag–Pt–Mg; Tl–As–Sb–Hg; Te–S–Ag–Pt–Al–Sc–(Gd–Lu)–Y; Fe–Cu–V–Ge–Co–In; Pd–Zr–Hf–W–Be and Ni–Mn–Co–Cr–Mg. The purpose of the assessment was to determine the nature and extent of potential contamination as well as to broadly assess possible impacts to human health and the environment. The results from the analysis of the collected samples in the vicinity of the mine revealed that As and Tl elements have the highest median values. Higher median values for Sb are obviously as a result of the past mining activities and as a result of area surface phenomena in the past.

Metal-based magnetic functional fluids with amorphous particles

Two metal-based magnetic functional fluids, Ga–Sn and Ga–In magnetic liquids, were fabricated by doping with Fe73.5Nb3Cu1Si13.5B9 metallic glass particles and nanoscale Fe3O4 particles, respectively.

Long persistent and photo-stimulated luminescence in Cr3+-doped Zn–Ga–Sn–O phosphors for deep and reproducible tissue imaging

A phosphor with remarkable long persistent luminescence features, Zn3Ga2Sn1O8:0.5 Cr3+, suitable for deep and reproducible tissue imaging has been rationally designed and successfully fabricated. This phosphor shows bright and long persistent luminescence over 300 h in the near-infrared region, and permits an enabling long-term, reproducible, real-time and reliable structural imaging of deep tissues. Moreover, the revived luminescence and persistent luminescence under the excitation of near-infrared incoherent light are also demonstrated to reveal an optional multiplexed detection. This new luminescent indicator will allow repeatable visualization of the structural and functional processes in cells, tissues and other complex systems. In addition, multifarious and systematic investigations are successfully carried out to unravel the nature of traps and also to verify the rationality of the material design.

Preparation of amorphous Ga–Sn–Zn–O semiconductor thin films by RF-sputtering method

Ga–Sn–Zn–O (GTZO) thin films were deposited on glass substrates via the radio-frequency (RF) magnetron sputtering method at room temperature. The target for the GTZO film deposition was a single GaSnZnO pellet. Various oxygen gas content levels in the sputtering gas ambient (0, 3.8, 7.4, and 10.7%) were used in the deposition experiments. The resistivity of GTZO films decreased from 78 to 19.5 Ω cm when the oxygen content was decreased from 10.7 to 0%. The carrier concentration significantly decreased from 1.81 × 1017 cm−3 to 5.98 × 1015 cm−3 when the oxygen content was increased from 0 to 10.7%. Incorporating oxygen into GTZO films suppresses oxygen vacancy formation, resulting in a reduction of generated free carriers. The mobility increases rapidly with increasing oxygen pressure. The highest mobility of 13.3 cm2/V s was obtained at a carrier concentration of 5.98 × 1015 cm−3.

Performance of Al–0.5 Mg–0.02 Ga–0.1 Sn–0.5 Mn as anode for Al–air battery in NaCl solutions

In this research, metal–air battery based on Al, Zn, Al–0.5 Mg–0.02 Ga–0.1 Sn and Al–0.5 Mg–0.02 Ga–0.1 Sn–0.5 Mn (wt%) is prepared and the battery performance is investigated by constant current discharge test in 2 mol L−1 NaCl solutions. The characteristics of the anodes after discharge are investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM). The corrosion behavior of the anodes is studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The results show that Al–Mg–Ga–Sn–Mn is more active than Al, Zn and Al–Mg–Ga–Sn anodes. The self-corrosion rate is found to be in the order: Al < Al–Mg–Ga–Sn–Mn < Al–Mg–Ga–Sn < Zn. It has been observed that the Al–air battery based on Al–Mg–Ga–Sn–Mn offers higher operating voltage and anodic utilization than those with others. SEM and EIS results of the alloy are in good agreement with corrosion characteristics.

Model of liquid gallium corrosion with austenitic stainless steel at a high temperature

The purpose of this study is to model the interaction between austenitic stainless steel and liquid gallium at a high temperature to predict the weight loss for potential application as a target material or coolant in an advanced nuclear system. In the present study, models for liquid gallium corrosion with austenitic stainless steel are studied and discussed. This paper presents a mathematical analysis of liquid gallium corrosion, especially the surface recession due to solubility and diffusion, in a static cell, as well as the mass exchange at the liquid/solid interface. Also, a mathematical analysis of liquid gallium alloy (Ga–Sn–Zn) corrosion is conducted in order to study its effect on the diffusion behavior after the addition of alloying elements. The results show that the predicted corrosion behavior agrees well with experimental data and the weight loss of austenitic stainless steel are significantly reduced in gallium alloy compared to those in pure gallium at high temperatures.

Investigation on hydrogen production using multicomponent aluminum alloys at mild conditions and its mechanism

A series of Al alloys with low melting point metals Ga, In, Sn as alloy elements were fabricated using mechanical alloying method. The phase compositions and morphologies of different Al alloys were characterized by XRD and SEM techniques. The reaction of the Al alloys with water for hydrogen evolving at mild conditions (at room temperature in neutral water) was studied. The results showed that there were no hydrogen yields for binary Al–Ga, Al–In, Al–Sn and the ternary Al–Ga–Sn alloys. The hydrogen yields were observed for Al–Ga–In and Al–In–Sn ternary alloys. The Al–In–Sn alloys showed an even faster hydrogen generation rate and higher yields than Al–Ga–In alloys. Based on the ternary Al–Ga–In and Al–In–Sn system, the hydrogen production property of quaternary Al–Ga–In–Sn was greatly improved. The hydrogen conversion efficiency of the optimized Al–3%Ga–3%In–5%Sn alloy was nearly 100% in tap water. The highest hydrogen generation rate reached 1560 mL/g min in distilled water or deionized water. It was suggested that both the embrittlement of Al by liquid Ga–In–Sn eutectic and the active points formed by intermetallic compounds In3Sn and InSn4 may be attributed to the high activity of Al–Ga–In–Sn alloys at room temperature.

Effect of composition on the reactivity of Al-rich alloys with water

Fe-bearing Al–Ga–In–Sn alloys were prepared by using arc melting under high purity argon atmosphere. Their microstructures were investigated by means of XRD, SEM/EDX, and the eutectic reaction of Al with grain boundary phase Ga–In–Sn (GIS) was measured using DSC. Fe dendrites were found to present on columnar Al grain surfaces. As the amount of low melting point metals (Ga, In and Sn) is 6 wt.% with a ratio of In:Sn of 15:7, these alloys just consist of Al(Ga) and In3Sn two phases. InSn4 was found in an alloy as its weight ratio of In:Sn approaches 1:1 with an extra addition of Sn (1 wt.%). The reactions of Al alloys with water were performed at different water temperatures ranging from 0.5 to 50 °C. Al reacted with water at a lower water temperature of 0.5 °C, but the reaction suspended within tens of minutes. Once water was heated to a higher temperature of about 15 °C, Al reacted with water again. The H2 generation rates measured at a water temperature of 50 °C depend on the compositions of alloys. Reasons concerning the reactivity of Al–water at different temperatures are discussed.

ChemInform Abstract: Thermoelectric Properties of Type‐VIII Clathrate Ba8Ga16Sn30 Doped with Cu.

AbstractSingle p‐ and n‐type crystals of the title clathrate are grown from Ga flux and Sn flux, respectively.

Thermoelectric properties and structural instability of type-I clathrate Ba8Ga16Sn30 at high temperatures

Type-I clathrate Ba8Ga16Sn30 is known as a typical example showing glass-like behavior in the thermal conductivity at low temperatures. We report on thermoelectric properties above room temperature for the p- and n-type single crystals which were grown from Ga–Sn double flux and Sn single flux, respectively. The measurements of electrical resistivity showed hysteretic behaviors when the sample was heated to 600K. Powder X-ray diffraction analysis indicated that the type-I structure changed to the type-VIII after the sample was heated to 600K. By using the data of Seebeck coefficient, electrical resistivity, and thermal conductivity, we estimated the dimensionless figure of merit ZT for the type-I Ba8Ga16Sn30. For the p- and n-type samples, the values of ZT reach 0.58 and 0.50 at around 450K, respectively, which values are approximately half of those for the type-VIII counterparts.

Thermoelectric properties of type-VIII clathrate Ba8Ga16Sn30 doped with Cu

The intermetallic clathrate Ba8Ga16Sn30 with type-VIII structure is one of the promising thermoelectric materials. We report on significant effects of Cu doping on both the crystal growth and thermoelectric properties of type-VIII clathrate Ba8Ga16Sn30. By using the Ga flux and Sn flux, respectively, the carrier type could be tuned as p- and n-types. The p-type single crystals were grown to approximately 6mm in diameter, which is twice as large as that grown without Cu. The crystals were characterized by electron-probe microanalysis and powder X-ray diffraction and used for the measurements of the electrical resistivity, Seebeck coefficient, and thermal conductivity. The values of the dimensionless figure of merit ZT of the p- and n-type crystals reached 0.88 and 1.45 at around 500K, respectively, the latter of which is the highest among all substituted systems of type-VIII Ba8Ga16Sn30. This enhancement of ZT is discussed in relation with the charge balance and modification of the band structure caused by Cu doping.

Predicting enthalpies of formation of Al–Ga–In, Al–Ga–Sn, Cd–Ga–Sn and Ga–Sn–Zn liquid alloys by molecular interaction volume model

The enthalpies of formation of Al–Ga–In, Al–Ga–Sn, Cd–Ga–Sn and Ga–Sn–Zn liquid alloys are calculated by molecular interaction volume model using only the coordination numbers and the binary infinite dilute enthalpies. The predicted values are compared with the experimental data; the results indicate that the model is reliable as well as convenient.

Temperature dependent magnetostrains in polycrystalline magnetic shape memory Heusler alloys

Abstract The transformation-induced strains with and without applied magnetic field and magnetostriction loops at different temperatures have been measured for polycrystalline ferromagnetic and metamagnetic shape memory Heusler alloys such as Ni Mn Ga, Ni Fe(Co) Ga and Ni Mn Sn, respectively. The results evidence a magnetic field oriented growth of martensitic variants during the martensitic transformation in Ni Mn Ga sample, whereas this effect is not evident in the other two alloys. In the Ni Mn Sn alloy, the isotropic volume magnetostriction dominates the anisotropic domain magnetostriction.

Sputter‐deposited Ga–Sn–Zn–O thin films for transparent thin film transistors

AbstractGa–Sn–Zn–O (GTZO) thin films were prepared on glass substrates at 100 °C by co‐sputtering of Ga‐doped ZnO and SnO2 targets. Characteristic properties of the films were investigated with varying oxygen gas content in the sputtering ambient. Whereas amorphous GTZO films were prepared with pure Ar sputtering, polycrystalline films were obtained with the addition of oxygen gas. With a proper mixing ratio of sputtering gases, O2/(Ar + O2) ∼2%, we could obtain GTZO films with good performances as an active channel material in thin film transistor (TFT); i.e, field effect mobility of 12.2 cm2 V−1 s−1, on/off current ratio of 109, and subthreshold voltage swing of 0.46 V decade−1.

Ternary Compounds in the Sn-Rich Section of the Ba–Ga–Sn System: Ba8Ga16–xSn30+x (1.1 ≤ x ≤ 2.8) Clathrates of Type-I and Type-VIII, and BaGa2–xSn4+x (x ≈ 0.2) with a Clathrate-like Structure

Systematic syntheses in the Ba–Ga–Sn system confirmed the existence of a new ternary phase BaGa1.79Sn4.21(2) (EuGa2Ge4 structure type; orthorhombic space group Cmcm, Pearson symbol oS28) with lattice parameters a = 4.5383(6) Å, b = 12.2486(16) Å, c = 14.3747(19) Å. The structure is best viewed as an open-framework based on tetrahedrally coordinated Sn/Ga atoms with Ba atoms enclosed in the voids within it. The new phase co-precipitates with two other compounds with very similar compositions—Ba8Ga14.5Sn31.5(4) (K4Si23 structure type; cubic space group , Pearson symbol cP54; a = 11.6800(12) Å), and Ba8Ga13.2Sn32.8(3), (Eu4Ga8Ge15 structure type; cubic space group , Pearson symbol cI54; a = 11.5843(7) Å). Detailed discussion on how syntheses affect the crystal chemistry, and the temperature dependence of the atomic displacement parameters, obtained from single-crystal structure refinements, are also reported in this article.