Ga-Sn Alloy Research Articles

Sn-doped β-Ga2O3 thin films grown on off-axis sapphire substrates by LPCVD using Ga-Sn alloy solid source

Adopting low pressure chemical vapor deposition (LPCVD), Sn-doped β-Ga2O3 thin films were heteroepitaxially grown on c-plane sapphire substrates with off-axis angles towards 〈11–20〉 direction. The influences of off-axis angle on crystal structures, electrical properties, surface morphology, and chemical compositions were thoroughly investigated. As a result, the crystallinity of the β-Ga2O3 films is improved with increasing off-axis angles because in-plane rotational domains are effectively suppressed, demonstrating a full width at half maximum (FWHM) down to 0.64°. Correspondingly, the Hall carrier mobility is promoted from 4.7 to 17.9 cm2/V·s at carrier concentration of 9 × 1017 cm−3, which is believed highly competitive among reported Sn-doped β-Ga2O3 films by LPCVD. These results demonstrate an alternative pathway to heteroepitaxially grow high electrical quality n-doped β-Ga2O3 films for the advancement of Ga2O3 materials and devices.

TWO TYPES OF GALLIUM EXPOSURE TO ALUMINUM

The effect of gallium on aluminum during their fusion is investigated. The corrosion rate of aluminum alloys with 1, 2 and 5 at % gallium content was experimentally determined, which was 0.001, 0.00101 and 0.00062 g/m2 · h, respectively, which is less than that of pure grade A99 aluminum – 0.0016 g/m2 · h. The rate of dissolution of these alloys in acidic and alkaline media is determined. X-ray phase analysis showed the homogeneity of the alloys under consideration. The morphology of aluminum alloys with gallium was studied, after exposure to an aggressive environment – a solution of hydrochloric acid. The possibility of obtaining hydrogen and nanoscale alumina by decomposition of water by activated gallium aluminum alloy is shown. Activation of the aluminum surface by gallium alloy occurs according to the Rebinder effect and the article presents a micrograph of the surface of aluminum treated with Ga-Sn alloy, clearly demonstrating this effect. When using metallic gallium in contact with aluminum, the interaction requires heating to a temperature above 30°C (the melting point of gallium is 29.7°C), the melting point of the eutectic composition 92Ga–8Sn is 20.0°C, which allows the interaction to begin at room temperature. At temperatures of about 4°C, activated aluminum can be stored for a long time. The quality of hydrogen obtained by decomposition of water should be higher than that obtained by cracking, and the cost is close to a well-developed technology of electrolysis of water and no more than 2 times the cost of its synthesis via cracking of hydrocarbons. Gallium and its liquid alloys are non-toxic, almost do not interact with water, activate aluminum, preventing the formation of a protective oxide film, penetrate into the intergranular space and aluminum easily interacts with water, forming hydrogen and aluminum hydroxide.

The liquid-liquid structure change in eutectic Ga-Sn alloy

• The liquid-liquid structure transition did occur around the liquidus temperature. • Another liquid-liquid structure transition did occur in the range from 1073-1273 K. • Below and above the liquidus temperature, the liquid exhibits differences in viscosity, coordination numbers, correlation radius of cluster. The effect of temperature on dynamic viscosity and atomistic structure in liquid eutectic Ga-Sn alloy have been investigated by using a torsional oscillating viscometer, an X-ray diffractometer and the ab initio molecular dynamics simulation. The results indicated that the liquid-liquid structure transitions did occur around the liquidus temperature and in the range from 1073-1273 K. Below and above these temperatures the liquid exhibits differences in viscosity, coordination numbers, correlation radius of cluster, which are reflected from structural changes of structural disorder and local atomic packing. This work will trigger a further study on the liquid-to-liquid crossover in the liquid-solid transition.

Self-healing boron-doped Sb2Se3 thermoelectric materials prepared using liquid metallic Ga–Sn alloys

Self-healing boron-doped Sb2Se3 thermoelectric materials prepared using liquid metallic Ga–Sn alloys

Magnetic Studies of Superconductivity in the Ga-Sn Alloy Regular Nanostructures.

For applications of nanolattices in low-temperature nanoelectronics, the inter-unit space can be filled with superconducting metallic alloys. However, superconductivity under nanoconfinement is expected to be strongly affected by size-effects and other factors. We studied the magnetic properties and structure of the Ga-Sn eutectic alloy within regular nanopores of an opal template, to understand the specifics of the alloy superconductivity. Two superconducting transitions were observed, in contrast to the bulk alloy. The transitions were ascribed to the segregates with the structures of tetragonal tin and a particular gallium polymorph. The superconducting-phase diagram was constructed, which demonstrated crossovers from the positive- to the common negative-curvature of the upper critical-field lines. Hysteresis was found between the susceptibilities obtained at cooling and warming in the applied magnetic field.

Structural and electronic changes in Ga-In and Ga-Sn alloys on melting.

The melting behaviour of surface slabs of Ga-In and Ga-Sn is studied using periodic density functional theory and ab initio molecular dynamics. Analysis of the structure and electronics of the solid and liquid phases gives insight into the properties of these alloys, and why they may act as promising CO2 reduction catalysts. We report melting points for slabs of hexa-layer Ga-In (386 K) and Ga-Sn (349 K) that are substantially lower than the pure hexa-layer Ga system (433 K), and attribute the difference to the degree to which the dopant (In or Sn) disrupts the layered Ga network. In molecular dynamics trajectories of the liquid structures, we find that dopant tends to migrate from the centre of the slab towards the surface and accumulate there. Bader charge calculations reveal that the surface dopant atoms have increased positive charge, and density of states analyses suggest the liquid alloys maintain metallic electronic behaviour. Thus, surface In and Sn may provide good binding sites for intermediates in CO2 reduction. This work contributes to our understanding of the properties of liquid metal systems, and provides a foundation for modelling catalysis on these materials.

A Ga-Sn liquid alloy-encapsulated self-healing microcapsule as high-performance Li-ion battery anode

• A Ga-Sn liquid alloy-encapsulated microcapsule is developed as self-healing Li-ion battery anode. • The liquid alloy microcapsules are prepared by using an oil-in-water emulsion. • Liquid alloy-encapsulated microcapsules exhibit high capacity and rate-performance. • Promising applications of Ga-Sn liquid alloy-encapsulated microcapsules is achievable. Engineering emerging anodes for lithium-ion batteries is of great significance. Here, we develop a self-healing anode composing of Ga-Sn liquid alloy infilling in a microcapsule. The microcapsules are prepared by using an oil-in-water emulsion. Liquid state of the Ga-Sn alloy in microcapsules is able to reduce structural failure on the basis of a self-healing mechanism during long-term cycling; the voids of microcapsules alleviate volumetric change of Ga-Sn alloy upon charge–discharge; and carbon shell improves the conductivity. The liquid alloy-encapsulated microcapsule anode exhibits a capacity of 711.6 mA h g −1 after 500 cycles and an ultrahigh Coulombic efficiency of 99.9 %. Moreover, the microcapsules present a recoverable rate-performance. Those properties enable the self-healing Ga-Sn liquid alloy-encapsulated microcapsules developed here to have a good potential for practical applications.

A high-performance room-temperature magnesium ion battery with self-healing liquid alloy anode mediated with a bifunctional intermetallic compound

Liquid metals with a self-healing property can address the passivation issue of Mg metal and the huge volume variation problem of solid alloy-type anodes in rechargeable magnesium ion batteries (MIBs). Liquid Ga-based anodes show great potentials in MIBs, however, being operated at room temperature is a great challenge. Herein, a novel strategy is proposed to enhance the room-temperature Mg storage performance of liquid eutectic GaSn (EGaSn) alloy through constructing a bifunctional intermetallic compound (Ag3Ga) layer on the current collector. This Ag3Ga layer could greatly improve the wettability of EGaSn on the substrate in the electrolyte environment. Moreover, operando X-ray diffraction confirms that Ag3Ga could participate the reversible alloying/dealloying reactions during the discharge/charge processes and thus provide an extra capacity. Eventually, the Ag3Ga-mediated EGaSn anode exhibits outstanding electrochemical performance towards Mg storage in both half and full cells at room temperature (∼24 and 21 °C), as benchmarked with state-of-the-art anodes in MIBs. Specially, the MIBs could be stably cycled up to 600 cycles in the half cell configuration, and 100 cycles in the full cell assembly. This work provides useful information on the development of advanced anodes for MIBs.

Experimental Research on the Temperature Characterization of a Miniature Phase Change Cells in the Blackbody for the On-Orbit Radiometric Calibration of Thermal Infrared Sensors

For on-orbit radiometric calibration of infrared (IR) satellite instruments, we have developed a blackbody source whose temperature can be accurately determined by use of miniature phase change cells to provide fixed points. The temperatures and reproducibility of six phase change cells containing H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O, Ga–Sn alloy, Ga–Zn alloy, phenyl salicylate (PS), succinonitrile, and Ga were accurately determined by the measurement of the phase change plateaux. The points were measured using the quasiadiabatic vacuum measurement system, which was developed by the National Institute of Metrology, China. The reproducibility time span of the Ga fixed point was as long as six years. Results indicated that the reproducibility values of multiple phase-change run-off point temperatures of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O, Ga–Sn alloy, Ga–Zn alloy, PS, succinonitrile, and Ga were 2.0, 3.6, 1.5, 3.5, 2.9, and 3.1 mK, respectively. Furthermore, a strong linear relation was observed between the heating power and the run-off temperature. With decreasing heating power, the temperature of the plateau decreased and approached the defined fixed-point value. All simulation results of the miniature fixed points were consistent with the experimental data.

Self-Healing Boron-Doped Sb2se3 Thermoelectric Materials Prepared Using Liquid Metallic Ga–Sn Alloys

Self-Healing Boron-Doped Sb2se3 Thermoelectric Materials Prepared Using Liquid Metallic Ga–Sn Alloys

Ab initio molecular dynamics study on the disordered Li-Ga-Sn system.

The eutectic Ga91.6Sn8.4 liquid metal could serve as the anode in Li-ion batteries to avoid dendrite growth issue and volume expansion, and maintain a good cycle life. However, the microstructure and the basic physical properties of the lithiated Ga91.6Sn8.4 are ignored in experiments and still unclear. In this work, we assume that a disordered structure is formed in the initial stage of lithiation of Ga91.6Sn8.4, and the structure, equilibrium density, thermal expansion coefficient, mixing enthalpy, self-diffusion coefficient and viscosity of the disordered Li-Ga-Sn system are investigated systematically by ab initio molecular dynamics. The radial distribution function, structure factor and bond angle distribution function are calculated to obtain local structure information. Our calculations show that the lithiation of Ga91.6Sn8.4 is exothermic, and for most cases, the diffusion coefficients for Li, Ga and Sn decrease with increasing Li content. Based on structural information and diffusion coefficients, we reveal that the lithiation of Ga91.6Sn8.4 will make the liquid Ga91.6Sn8.4 alloy form a solid-like structure. With the increase of Li content, it is more likely to form a solid-like structure. Furthermore, our simulations reveal that the chemical interaction of Li-Sn and Li-Ga is stronger than that of Ga-Sn, and Li is prone to combine with Sn firstly in the lithiation process of Ga91.6Sn8.4.

A High‐Performance Room‐Temperature Li||Ga–Sn Liquid Metal Battery for Grid Energy Storage

Herein, a room‐temperature liquid metal battery (LMB) with a solid lithium anode electrode and gallium–tin (Ga–Sn) alloy cathode electrode is reported. With the improved wettability of the electric collector and grain‐refined liquid metal droplets cathode, the aforementioned LMB exhibits good cyclic reversibility and negligible self‐discharge. The result shows that the assembled Li||Ga–Sn battery has a satisfactory specific capacity (409 mAh g−1) and high energy efficiency (up to 92%). The low melting point Ga–Sn alloy can construct fast kinetics for the redox reaction and improve the electrode reaction kinetics, imparting the Li||Ga–Sn system with high discharge voltage (0.77 V at 1C) and smaller polarization voltage at different current densities, which ensure the high Coulomb efficiency and good rate performance of the battery. Moreover, the battery stably cycles at 35 °C for 60 cycles at the 1C rate, with no significant capacity degradation. With good electrochemical performance, simple structure, easy maintenance, and high safety, this room‐temperature Li||Ga–Sn battery may be a promising choice for power grid energy storage applications.

Solid–liquid phase transition induced electrocatalytic switching from hydrogen evolution to highly selective CO2 reduction

Conventional strategies for modifying electrocatalysts for efficient CO2 reduction are mainly based on doping, defect/morphology engineering, substrate design and so on. In most cases, these methods can only tune their structures, electronic states and thereby catalytic properties in a gradual way. Here we report that the solid–liquid phase transition of Ga–Sn/Ga–In alloys can induce an instant and radical transformation of their atomic and electronic structures during electrocatalysis, which dramatically impacts their catalytic properties. The transition of Sn/In active components from phase-segregated clusters to dispersed single atoms during melting results in a unique electronic structure through further reduction of both metallic Sn/In and Ga. Such atomic/electronic structure transitions can correlate well with suppression of the hydrogen evolution reaction and an enhanced formate Faradaic efficiency from 95%. This two-state switching strategy may be extended to other catalytic reactions to determine correlations between their structures and catalytic properties. Common strategies for catalyst design explore ways of fine-tuning continuous structure–property relationships. Here, the abrupt solid–liquid transition of Ga–In and Ga–Sn alloys is shown to have a profound impact on the CO2 electroreduction performance, with the molten alloy achieving a Faradaic efficiency of 95% formate production.

A Stretchable Lithium-Ion Battery Using Liquid Metal Nano Particle

Introduction Stretchable devices have been highly demanded because of wearable devices in the IoT society. Stretchable lithium ion batteries are crucial to growth of IoT society, since the current developed devices possesses only interface part. The batteries and devices require higher stretchability and robustness to deformation. Liquid metal (LM) is one of the prominent materials for stretchable sensors(1) and wiring circuit(2). In addition, LMs have self-healing characteristics(3) and high capacity (Ga:769 mAh/g, Sn:990 mAh/g) in lithium ion batteries. Here, we investigated the electrochemical characteristics and improvement of robustness using liquid metal nano particles (LMNP) anode in stretchable lithium ion batteries. In this study, stretchable 3D porous LMNP electrodes are fabricated and assembled into stretchable batteries. The stretchable batteries consist of stretchable LMNP and LiFePO4 (LFP) electrodes based on 3D porous polydimethylsiloxane (PDMS)/Ecoflex/Super P carbon composites, stretchable separator, [Li(G4)][TFSI] electrolyte and stretchable package. The batteries have high stretchability and robustness to deformation. Experiment 3D porous PDMS/Ecoflex/Super P carbon composites were used for stretchable electrode substrates. The porous structure was prepared by sacrifice-template method using sugar(4). 3D porous PDMS/Ecoflex/Super P carbon composites was composed of PDMS, Ecoflex with the weight ratio of 6:4 and coating Super P carbon on the surface. LMNP was prepared by ultra-sonication GaSn (Ga:Sn=88:12) alloy. The LMNP alloy was used as active materials of anode. The anode slurries were prepared by mixing the LMNP, Super P carbon, poly(vinylidene fluoride) (PVDF) in N-methyl-2-pyrrolidione (NMP) solvent. LFP was used as active materials of cathode. The cathode slurries consisted of LFP, Super P carbon, PVDF. Stretchable electrodes were fabricated by drop cast method with the electrode slurries on the 3D porous substrates. [Li(G4)][TFSI] was composed of LiTFTI and Tetraethylene glycol dimethyl ether (G4). Stretchable batteries were assembled using the PDMS/Ecoflex/Super P carbon/LMNP anode, PDMS/Ecoflex/Super P carbon/LFP cathode, stretchable separator and stretchable packaging. The nickel/aluminum tabs are attached to PDMS/Ecoflex/Super P carbon/LMNP and PDMS/Ecoflex/Super P carbon/LFP electrode by using small amount of epoxy resin adhesive(Fig. 1). Results and Discussion To investigate the electrochemical characteristics of the stretchable electrode on lithium ion batteries, we respectively conducted galvanostatic tests of the stretchable LMNP anode and the stretchable LFP cathode in half-cell configurations paired with lithium metal as counter and reference electrode. The results show the electrodes can charge/discharge on lithium ion batteries at 1 C. In addition, the electrochemical performance of the stretchable LMNP electrode was investigated. The charge/discharge curves were measured after 100% strain-release cycle 50 and 100 times. The results of the stretchable LMNP electrode showed the capacity retention was higher than the stretchable Si NP (silicone nano particle) electrode. The LMNP used as active materials improve robustness to stretching were confirmed. The full cells were tested using PDMS/Ecoflex/Super P carbon/LMNP and PDMS/Ecoflex/Super P carbon/LFP electrode with charge/discharge measurement. As a result, the full battery could work. Acknowledgement This work was supported by JST CREST Grant Number JPMJCR1905, Japan, by the Japan Science and Technology Agency, PRESTO Grant Number JPMJPR18J2, and by JSPS Grant-in-Aid for Challenging Exploratory Research. References (1) Yuji Gao et al, Advanced. Materials , 2017, 1701985(2) Guangyong Li et al, Sensors and Actuators B , 2015, 221, 1114-1119(3) Yingpeng Wui et al, Energy & Environmental Science , 2017, 10, 1854-1861(4) Hongsen Li et al, Advanced. Materials , 2017, 1700898 Image Figure 1 Self-healing behavior of LMNP (left). Schematic diagram of stretchable battery (right). Figure 1

Spaceborne radiance temperature standard blackbody for Chinese high-precision infrared spectrometer

As a radiance temperature standard source for the Chinese high-resolution spectrum infrared spectrometer, the National Institute of Metrology, China, developed a spaceborne radiance temperature standard blackbody (SRTSB) combined with a series of miniature phase change fixed points (MPCFPs) for temperature calibration and emissivity verification using a thermal radiation loop (TRL). The MPCFPs of the SRTSB contain H2O, Ga, Ga–Sn alloy, and phenyl salicylate. The TRL is used to measure the emissivity of the spaceborne blackbody on the basis of controlling environmental radiation. Experimental results show that the blackbody emissivity is higher than 0.998 and the temperature control stability is better than 5 mK. Temperature control uniformity at the cavity bottom and axial are better than or equal to 11 mK and 38 mK, respectively, in the working temperature range of 268.15 K to 331.15 K.. The repeatability of the MPCFPs is less than 5 mK, and the results of the continuous phase transition of the MPCFPs are in a clear temperature plateau. The expanded uncertainty of the SRTSB is lower than or equal to 0.084 K (k = 2).

Liquid metal Ga-Sn alloy based ferrofluids with amorphous nano-sized Fe-Co-B magnetic particles

Amorphous Fe-Co-B nano-sized magnetic particles were prepared and firstly introduced into Ga91.6Sn8.4 alloy to fabricate liquid metal-based ferrofluids. The Fe-Co-B particles are amorphous and spherical with an average particle size of 10.6 nm. The saturation magnetization of amorphous Fe-Co-B nanoparticles after annealing treatment at 550 °C is 81 emu/g, which is higher than that of Fe-Co-B nanoparticles without and after annealing treatment at 450 °C. The annealed Ga91.6Sn8.4 alloy-based ferrofluids with amorphous Fe-Co-B nanoparticles exhibit high stability, which is superparamagnetic with a saturation magnetization of 2.57 emu/g. Besides, the Ga91.6Sn8.4 alloy-based ferrofluids show temperature-sensitive magnetic property. The magnetoviscous property demonstrates that the annealed Ga91.6Sn8.4 alloy-based ferrofluids show relatively strong magnetic responsiveness. The hysteresis curves of viscosity–magnetic field show the annealed Ga91.6Sn8.4 alloy-based ferrofluids have superior reversibility and exhibit a desirable high-temperature performance.

Research on thermal properties of phase change thermal control materials Bi-21In-18Pb-12Sn and Ga-13.5Sn with low melting point

Two novel low melting pointing metals (LMPMs), Bi-21In-18Pb-12Sn alloy and Ga-13.5Sn alloy as phase change materials (PCMs), were firstly proposed to work for thermal management in aerospace applications. Their phase change characteristics and thermal stability were investigated in comparison with that of conventional paraffin PCMs (i.e. C26H58 and C17H36). The results indicate that the latent heat per unit volume in the LMPMs is higher than that of the paraffin PCMs, leading to much better thermal capacity of the former, and this can effectively reduce the volume proportion of LMPMs in use. LMPMs exhibit excellent thermal conductivity compared with the paraffin PCMs, and this contributes to rapid absorption of the heat released by the temperature-controlled target, and consequently the temperature of the target could remain stable near the phase change temperature. Besides, the Al2O3 coating by the spraying method could act as effective corrosion inhibitor in protecting Al alloy container used for electronic packaging from the liquid Ga-Sn alloy. The temperature control characteristic and temperature gradient of LMPMs consequently could suit the applied requirement of spacecraft device operated in vacuum condition. Therefore, low melting point metals with better thermal conductivity and stability would be promising candidates for PCMs applied in the field of aerospace.

Evaluation of nanometer-sized zirconium oxide incorporated Al—Mg—Ga—Sn alloy as anode for alkaline aluminum batteries

Abstract Zirconium oxide nanoparticles with 0.4 wt.% and 0.8 wt.% are incorporated into the Al—0.65Mg—0.05Ga— 0.15Sn (wt.%) alloy anode (base alloy) in order to improve the performance of the resulting anodes. Electrochemical characterization of the reinforced alloys was done by potentiodynamic polarization, electrochemical impedance spectroscopy and galvanostatic discharge and corrosion behavior was evaluated using self-corrosion rate and hydrogen evolution in 4 mol/L KOH solution. The surface morphology of the alloys was also studied using field emission scanning electron microscope (FESEM). The obtained results indicate that the base alloy shows high corrosion rate in 4 mol/L KOH solution by releasing 0.47 mL/(min·cm2) hydrogen gas, whereas the alloy containing 0.8 wt.% ZrO2 provides the lowest hydrogen evolution rate by releasing 0.32 mL/(min·cm2) hydrogen gas. Furthermore, by increasing zirconium oxide nanoparticles, the corrosion current density of the aluminum anodes is decreased and their corrosion resistance increases significantly compared to the base alloy in alkaline solution. In addition, nanometer-sized zirconium oxide incorporated anodes exhibit the improved galvanic discharge efficiencies, so that 0.8 wt.% nano-zirconium oxide incorporated base alloy displays the highest power density and anodic utilization compared with the others in 4 mol/L KOH solution.

The dissection of atomic clusters with local structure in Ga-Sn alloy melts

The statistic short-range order (SRO) structure parameters of the Ga-Sn alloy melt are obtained with the X-ray diffractometer. The local atomic and electronic structures around the absorption atoms of Ga and Sn elements are detected by X-ray absorption fine structure spectrum. Centered on the absorption atom, the atom cluster structure was dissected and the atom cluster model was established. Unlike the ordinary liquid metal structure, the local atomic structure demonstrates that the liquid Ga-Sn alloy is not characterized by a dominant icosahedral short-range order. Specially, Sn atoms aggregate in Ga91.6Sn8.4 alloy, giving rise to a phase separation that exhibits compositional disorder.

The Interaction of Sn-Ga Alloys and Au Coated Cu Substrates

Ga and Ga-based alloys appear to be promising materials for low temperature soldering in microelectronics. This research involved an analysis of the joint interfaces that resulted from reactions between a eutectic Ga-Sn alloy and Au coated Cu substrates at both room temperature and 100°C. At both temperatures the intermetallic CuGa2 accounted for the majority of the interfacial microstructure. This study has shown the possibility of using eutectic Ga-Sn alloys in low temperature soldering applications, as well as the advantages of Synchrotron XFM techniques in characterising trace element distributions in solder joints.