Elemental Indium Research Articles

Heavy Pentaisopropylcyclopentadienyltriylenes and their Heterobimetallic Complexes.

A series of triylenes of the heavy group 13 elements gallium, indium and thallium, carrying the pentaisopropylcyclopentadienyl ligand is reported. The compounds were characterized in solution and in the solid-state and their donor ligand properties in heterobimetallic complexes were investigated, whereby a series of tungsten carbonyl complexes was isolated. Furthermore, a new synthetic route towards a previously described lithium-aluminum heterobimetallic dimetallocene is reported, which also enabled the isolation of a heterobimetallic polydecker of lithium and gallium.

Synthesis and Reactivity of a Dialane-Bridged Diradical.

Radicals of the lightest group 13 element, boron, are well established and observed in numerous forms. In contrast to boron, radical chemistry involving the heavier group 13 elements (aluminum, gallium, indium, and thallium) remains largely underexplored, primarily attributed to the formidable synthetic challenges associated with these elements. Herein, we report the synthesis and isolation of planar and twisted conformers of a doubly CAAC (cyclic alkyl(amino)carbene)-radical-substituted dialane. Extensive characterization through spectroscopic analyses and X-ray crystallography confirms their identity, while quantum chemical calculations support their open-shell nature and provide further insights into their electronic structures. The dialane-connected diradicals exhibit high susceptibility to oxidation, as evidenced by electrochemical measurements and reactions with o-chloranil and a variety of organic azides. This study opens a previously uncharted class of dialuminum systems to study, broadening the scope of diradical chemistry and its potential applications.

The enrichment mechanism of indium in Fe-enriched sphalerite from the Bainiuchang Zn-Sn polymetallic deposit, SW China

Dispersed metals, such as indium and cadmium, are widely used in certain high-tech applications and are important resources for world economies. Sphalerite is an important host mineral for indium, cadmium and other trace elements which can record genetic information in hydrothermal systems. The Bainiuchang Zn-Sn polymetallic deposit, located in the southwest margin of the Yangtze Block, has substantial zinc concentrates with indium and cadmium mineralization. In this study, we examined different sphalerite grains from this deposit with elemental mapping, in-situ trace element geochemistry and S-Pb isotopic composition. The discrepancy of indium and Zn/Cd ratio suggest that there are at least two generations of sphalerite. The mineralization of indium is mainly enriched in marmatite [(Zn,Fe)S)] from cassiterite-bearing ore, rather than in that from cassiterite-poor ore. The mineralization of cadmium occurred in all types of ore. The relevance of trace elements suggests that indium can be incorporated into sphalerite by a couple substitution of (In, Ga)3+ + (Cu, Ag)+ ↔ 3(Zn, Fe)2+, whereas Fe, Cd can be incorporated into sphalerite by substitutions of Fe2+ ↔ Zn2+ and Cd2+ ↔ Fe2+. Sulfur (δ34SV-CDT =+2.43 to +3.88 ‰) and lead (206Pb/204Pb = 18.346–18.396, 207Pb/204Pb = 15.675–15.691) isotopic compositions indirectly suggest that indium and cadmium in the Bainiuchang Zn-Sn polymetallic deposit may be sourced from magmatic-hydrothermal fluids associated with Late-Cretaceous magmatic activities in this district.

Regulating localized state electron and ordered electron transfer in Cu2Se using Indium element for efficient heterogeneous Fenton-like process

Local electron density at the reaction center atoms is closely related to the H2O2 activation performance of a heterogeneous Fenton-like catalyst. However, the random electron transfer often restricts the oriented electron delivery to the active center. In this study, we proposed that only efficient electrons and their ordered transfer were desirable to boost Cu(II)/Cu(I) cycle for H2O2 activation based on regulation of local electron density and electron transfer efficiency of Cu atoms in Cu2Se. Experimental results and density function theory (DFT) calculation proved that Indium atom can drive electrons to accumulate on Cu active center and provide an efficient electron transfer pathway in CuInSe2 (from Se → Cu to In → Se → Cu). Hence, compared with Cu2Se, more reductive electrons can participate in the H2O2 activation process for CuInSe2, which resulted in much more efficient ofloxacin (OFX) degradation with a TOC removal rate up to 71.5 %. The electron exchange capacity of CuInSe2 was further regulated by changing the atomic ratios of Cu and In elements including CuInSe2, Cu1.5In0.5Se2 and Cu1.75In0.25Se2. CuInSe2 had the lowest electron exchange capacity and exhibited the highest reaction activity with a radical transformation efficiency from H2O2 of 9.83 × 10-4, in contrast, the value for Cu1.75In0.25Se2 was 2.78 × 10-4. We provided a new insight for improving the heterogeneous Fenton catalytic performance.

A clean and short process for the preparation of refined indium and investigation of migration distribution pattern of impurities thallium and tin via vacuum distillation

In this study, a novel two-stage vacuum distillation method was proposed to refine crude indium to prepare refined indium. Low-temperature distillation (1223K, holding time of 3h) and high-temperature distillation (1473K, holding time of 5h) were conducted under a system pressure of 7 × 10−3Pa to successfully purify crude indium (99 wt%) to refined indium (99.995 wt%). This strategy can replace the traditional electrolytic process for the clean production of refined indium and achieve the goals of environmental protection. The vapor-liquid equilibrium (VLE) values of indium-based binary alloys were calculated using the molecular interaction volume model (MIVM), and a VLE phase diagram was drawn. Optimal temperatures of 1173K for low-temperature and 1373K for high-temperature distillation were determined based on the VLE phase diagram, and good purification was achieved. Moreover, this study reveals the migration distribution pattern of typical impurity elements (e.g., Tl and Sn) in crude indium in the low and high-temperature distillation sections, further improving the refining effect. Notably, the combination of MIVM simulations and experiments can obtain optimal experimental parameters for segmental vacuum distillation and further help to avoid the waste of raw materials and energy caused by pre-experiments, realizing the clean and efficient production of refined indium.

Unlocking the potential of e-waste: A material quantification analysis of Cu, Cr, In, Mg, Nb, and Nd in the EU

Waste electronics present a growing concern due to their economic value and material intensification, making proper collection and recycling essential for sustainable growth. However, quantifying the size and composition of waste flows is challenging. Using a material flow analysis this study combines electronic waste flows and product compositions of six selected elements (chromium, copper, indium, magnesium, neodymium, and niobium) based on their significance in the electrical and electronic products (EEE) in the EU. The study found that in 2018, 52 % of all WEEE generated in EU28+3 was properly collected and recycled, and the remaining 48 % were unreported or unaccounted for of which the selected elements represented 5 %, representing a combined loss of €1.41 billion. The obtained results provide a much-needed perspective to map electronic products on a material level for circular material supply. Proper collection and recycling of WEEE are crucial for sustainable growth and the recovery of valuable materials.

Investigation of the Structural and Mechanical Properties of ((82-X) Sn –XCu -18 In) % Alloy with X= 1,2,3,4and 5

Materials Science is concerned with the development or synthesis of new materials . For this reason our interest is focused on the fabrication of new materials , such as lead free solder alloys . Sn-In alloys offer very low melting points and bond well with copper .This study aims to investigate The Structural and mechanical properties of (82-x)Sn -18In alloys with added copper .The Samples were prepared by melting technology From high purity (99 %) elements tin ,indium and copper .XRD showed the formation of a single phase hexagonal structure with a small copper plane, and the addition of copper decreased the particle size of the (82-x)Sn -18 In. The creep test results showed that Cu-containing solder alloys exhibited significant improvements in creep resistance. However, the average activation energy decreases with copper addition from 0.322 to 0.247 eV.

Optical Characterisation of Plasmonic Indium Lattices Fabricated Via Electrochemical Deposition

Indium is an emerging plasmonic material that offers to extend the plasmonic applications given by gold and silver from the visible to the ultraviolet spectral range, with applications in imaging, sensing, and lasing. However, due to the high-vapor pressure/low melting temperature of indium, nanofabrication of pre-defined metallic indium nanostructures is non-trivial.In this work, we show the potential of selective area electrochemical deposition for the manufacturing of large-area arrays of indium pillars, which can be used for plasmonic applications. We combine electrochemical deposition with substrate-conformal imprint lithography to realize these large-scale indium nanoparticle arrays, having well-defined dimensions. This template growth results into well-defined hexagonal array of pillars with a mean height of 235 nm having a standard deviation of 60 nm.To highlight the potential of this electrochemical-based technique for plasmonic applications, we have performed angle-dependent extinction measurements using s-polarized light and using a RI matching oil. We found that these indium nanopillar arrays exhibit a strong plasmonic response due to the coupling to the plasmonic surface lattice resonances (SLRs). Furthermore, we have simulated the optical response of this indium nanopillar array using finite difference time domain (FDTD) simulations. In these simulations, we included the morphology obtained from SEM and the electrical permittivity of elemental indium. We found that the simulated extinction spectra agree well with the experimentally obtained spectra at 0˚ and 8˚ incidence, despite the polydispersity of the indium pillar height and defects in the hexagonal array.Our results therefore demonstrate the possibility of realizing large-area fabrication of indium plasmonic nanoparticles, which can be used for plasmonic applications. Given the low-cost and scalable nature of this technique, this work opens new possibilities in the design and fabrication of large-area plasmonic metasurfaces that operate in the UV spectral range. Future extensions of this work may leverage the indium mask-constrained growth to tailor even further the shape of the nanoparticle and hence give a powerful tuning knob to tailor plasmonic resonances.

Effective attempt towards enhancing hydrogen storage performance of LPSO phase contained high-capacity Mg-based alloy by Indium

To explore more possibilities for hydrogen economy, Mg-based alloys containing long period stacking ordered (LPSO) phase for solid-state hydrogen storage deserve attention. In this paper, indium (In) element is adopted to alter the de/hydrogenation abilities of Mg–Y–Zn alloys. The relationship between microstructural features and hydrogen storage behaviors of Mg95Y3Zn2-xInx (x = 0, 1 and 2 at.%) alloys are discussed in detail. Indium element can modify the morphology of LPSO phase and more Mg interfaces are obtained. LPSO phase cannot be generated when Zn is completely replaced by In element; instead α-Mg grains and eutectic phase (Mg + MgYIn) the constitute the In2 alloy. Element In benefits the activation process of the alloys in this paper, which helps the alloy particles to be hydrogenated quickly in the first hydrogenation. Specifically, 1 at.% In substitution for Zn accelerates dehydrogenation and the dehydrogenation temperature reduces by 11 °C. The benefits of In element for dehydrogenation behaviors mainly come from increased Mg grain boundaries, larger MgH2 lattice constants with weaker Mg–H bonds, uniformly distributed nanoscale YH2/YH3 phase.

Structural, Optical, and Electrical Properties of SnO2–CdO–In2O3 Films Prepared by Magnetron Co‐sputtering

SnO2–CdO (SCO) films and SnO2–CdO–In2O3 (SCIO) films are successfully deposited on Si (100) and glass substrates by radio frequency and direct current magnetron co‐sputtering. The films are characterized by X‐ray diffraction, scanning electron microscope, energy‐dispersive X‐ray spectroscopy, ultraviolet visible near‐infrared spectroscopy, and four‐point probes. SCO films exhibit Cd2SnO4 (011) preferred orientation, and the SCO film deposited at the sputtering power of 80W exhibits excellent crystalline quality and transmittance. The arrangement of clusters changes from sparse to dense when the indium element concentration increases. The resistivities of SCIO films are of two orders of magnitude lower than those of the SCO films. However, the visible light transmittances decrease slightly and the optical bandgap values decrease from 5.00 to 4.85 eV. The results indicate that the indium element plays an important role in improving the electrical properties of SCO films. SCIO films are expected to be a good candidate for transparent conductive films.

Exploring the role of indium on the microstructure evolution and interface bonding behavior of brazing diamond abrasive with modified Cu–Sn–Ti

In the brazed joints prepared by Cu-Sn-Ti filler metal, it was found that the filler metal has poor wettability to diamond and diamond abrasive grits are prone to uneven wear resulting in low efficiency of diamond tools and difficulty in achieving the expected processing which are the key factors restricting the performance of brazed diamond tools with Cu based filler. This study aims to improve the wettability of Cu-Sn-Ti filler metal and the brazed joint wear resistance. For this purpose, a new Cu-Sn-Ti-Ga-In composite filler metal was proposed. In this experiment, the subcooling degree and microstructure morphology of the new filler metal were investigated, the microhardness and shear strength of the filler metal were determined, and the shear fracture morphology was analyzed. Wetting tests were conducted on graphite plates to study the effect of indium elements on the wettability of the filler metals. Brazed joints were also prepared, and the crawling morphology of the filler metal on the diamond surface and the wear marks of the diamond abrasive after the frictional wear test were observed. The test results show that Sn3Ti5 is a solid solution is favorable to explain some phenomena. The indium element can increase the subcooling of the filler metal, thus promoting the refinement of Sn3Ti5, and the formation of eutectic microstructure. In brazed joints, indium increases the wettability of the filler metal on the diamond surface thus increasing the climb height and reducing the uneven wear rate, and the brazed joints have the best cutting performance when the filler metal is added with 1 wt% of indium element.

Controlled Growth of Indium Oxide Nanowires for Gas Sensing Application.

The In2O3 nanowires have attracted enormous attention for gas sensor application due to their advantageous features. However, the controlled synthesis of In2O3 nanowires for gas sensors is vital and challenging because the gas sensing performance of the nanowires is strongly dependent on their characteristics. Here in this patent, we fabricated In2O3 nanowires on SiO2/Si substrate via a simple thermal vapor deposition method with the Au thin film as the catalyst. The growth temperatures were controlled to obtain desired nanowires of small size. The grown In2O3 nanowires were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The ethanol gas sensing properties were tested under the dynamic flow of dry air and analytic gas. The synthesized In2O3 nanowires have the potential for use in ethanol gas sensor application. In2O3 nanostructures grown at different temperatures ranging from 600 to 900oC have different morphologies. The sample grown at 600oC had a morphology of nanowire, with a diameter of approximately 80 nm and a length of few micrometers. Nanowires grown at 600°C were composed of oxygen (O) and indium (In) elements, with the atomic ratio of [O]/[In] = 3/5. The nanowire was a single phase cubic structure of In2O3 crystal. The In2O3 nanowire sensor showed typical n-type semiconducting sensing properties. The response decreased from 130 to 75 at 100 ppm when the working temperature decreased from 450°C to 350°C. The nanowires grown at 600°C by the thermal vapor deposition method had the best morphology with a small diameter of about 80 nm and a length of few micrometers. The In2O3 nanowires had a good ability to sense ethanol at varying concentrations in the range of 20 ppm to 100 ppm. The In2O3 nanowires can be used as building blocks for future nanoscale gas sensors.

Two-Dimensional Metal Coordination Polymer Derived Indium Nanosheet for Efficient Carbon Dioxide Reduction to Formate.

Main group indium materials have been known as promising electrocatalysts for two-electron-involved carbon dioxide reduction to produce formate, which is a key energy vector in many industrial reactions. However, the synthesis of two-dimensional (2D) monometallic nonlayered indium remains a great challenge. Here, we present a facile electrochemical reduction strategy to transform 2D indium coordination polymer into elemental indium nanosheets. In a customized flow cell, the reconstructed metallic indium exhibits a high Faradaic efficiency (FE) of 96.3% for formate with a maximum partial current density exceeding 360 mA cm-2 and negligible degradation after 140 h operation in 1 M KOH solution, outperforming the state-of-the-art indium-based electrocatalysts. Moreover, in and ex situ electrochemical analysis and characterizations demonstrate that the enhanced exposure of active sites and mass/charge transport at the CO2 gas-catalyst-electrolyte triple-phase interface and the restrained electrolyte flooding are contributing to producing and stabilizing carbon dioxide radical anion intermediates, thus leading to superior catalytic performance.

Annealing effect on the barrier characteristics and interface properties of Au/Pt/Ti/n-InAlAs Schottky contacts

A comprehensive study of the annealing effect (300–400 °С) on the electrical properties, morphology and chemical composition of the Au/Pt/Ti/n-InAlAs interface (Schottky contact) is carried out. It is shown that the Schottky contact pre-annealing during the formation or primary short (∼1 min) annealing significantly increases the barrier height to the standard 0.68–0.7 eV with an ideality factor close to 1.1 due to the formation of a homogeneous amorphous TiAs layer with a small metallic (elemental) indium content. A further annealing at temperatures 300–350 °С for up to 20 min does not lead to significant changes in the morphology and electrical parameters of the Schottky contact. The annealing at the temperature of 400 °С (∼10 min) leads to an increase in the barrier height and the ideality factor to the values of 0.73 and 1.3, respectively. In this case, the formation of an about 20 nm thick TiAs layer and indium clusters shaped as a pyramids at the Ti/InAlAs interface is also observed. Analysis of the temperature dependences of Schottky barrier parameters within the Tung model showed that only structural changes at the interface after the 400 °С annealing lead to a significant increase in the Ti/InAlAs Schottky contact homogeneity, reducing the density of local regions with a lowered barrier height.

Progress of Deep Resources Exploration and Mining (DREAM) program in China: Critical minerals

China launched the Deep Resources Exploration and Mining (DREAM) program in 2016. Since then, the program has made significant progress in the exploration of critical minerals, such as rare earth, rare, and rare scattered metals. A “five-in-one” model, based on climate, landform, parent rocks, carrier minerals, and pH values of weathering crust, has been established for rare earth prospecting in South China. It has led to a major breakthrough in the discovery of a new type of ion-adsorption rare earth deposit in the weathered crust of low-grade metamorphic rocks in southern Jiangxi, South China. A pegmatite beryllium (Be), skarn beryllium-tungsten (Be-W), cassiterite sulfide tin-tungsten-beryllium (Sn-W-Be), independent fluorite, and lead-zinc (Pb-Zn) vein five-in-one model was developed for the prospecting of rare metals such as Be and W and polymetals in the Zhaxikang-Cuonadong ore-concentrated area of the eastern Himalayas. A series of metallogenic models has been proposed for the investigation of lithium (Li) resources, leading to important breakthroughs in the prospecting of large to superlarge Li deposits in the Jiajika (western Sichuan), Dahongliutan (southwestern Xinjiang), and Xiaoshiqiao (central Yunnan) ore fields. Meanwhile, the DREAM program has achieved significant advancements in its knowledge of the ultranormal enrichment of indium, germanium, gallium, niobium, and rare earth elements in the western Yangtze block, Southwest China.

An effective strategy of indium half-doping to stabilize the structure and improve optoelectronic characteristics of Tl-Co based double perovskite: First principles study

Doping can improve the structural stability and photoelectric properties of perovskite materials. In this study, indium element was added into Tl-Co double based perovskite material to stabilize its structure and improve its photoelectric performance. The results show that the doped material Cs2In0.5Tl0.5CoX6(X = I, Br, Cl) has better ductility and stability than the original Cs2TlCoI6 by elastic constants and phonon spectra. Moreover, indium doping can improve the band structure of Tl-Co double-base perovskite materials, such as changing the band value to the optimal band gap value of solar energy absorber and transforming from indirect band structure to quasi-direct band structure. In terms of optical properties, indium doping can expand the wavelength range of the material's light absorption, making its absorption spectrum more matching with the simulated AM1.5 spectrum. Cs2In0.5Tl0.5CoCl6 is proposed to be a promising candidate for optoelectronic applications based on its structural stability, bandgap value and optical absorption spectrum.

Structural and Improper Ferroelectric Properties of TbInO3 Single Crystal Grown by Laser Floating Zone

The honeycomb TbInO3 has attracted wide research attention due to its fascinating physical properties. However, TbInO3 single crystal was difficult to grow owing to the high melting point and serious volatilization of indium during the crystal growth. In this study, the volatilization of the indium element was effectively suppressed by controlling the growth atmosphere and pressure. The excess ratio of indium oxide was determined, and pure hexagonal TbInO3 crystal was obtained by the laser floating zone method. Systematic studies on the crystal structure and optical and ferroelectric properties were carried out. The structure distortion resulted in the improper geometric ferroelectric revealed by single crystal diffraction and Raman spectrum measurements. The topological vortex domains and P-E hysteresis loop demonstrated the presence of ferroelectricity. TbInO3 crystal has great potential application in vortex memory.

Indium removal by Aspergillus niger fungal pellets in the presence of selenite and tellurite

The feasibility of simultaneous removal of indium, selenite and tellurite using biological reduction by Aspergillus niger fungal pellets is explored. Initially, batch experiments were conducted to study the capability of A. niger pellets to remove indium, selenium and tellurium in different combinations. The indium removal efficiency ranged between 52.3 and 65.6 % at 10 mg/L, with a maximum removal (~65 %) in incubations with only indium or indium with tellurite. The tellurium removal efficiency was maximum (76.7 %) in experiments with indium, but dropped drastically to 47.2 and 33.7 %, respectively, when selenite and indium were incubated together. The selenite removal efficiencies of the A. niger pellets were more consistent (50.2–59.5 %) for different experimental combinations and were not affected by either indium or tellurium. Further characterization of fungal biomass showed accumulation of mainly elemental Se and Te nanoparticles within the pellets. In addition, XRD analysis showed the formation of indium selenide and indium telluride during their simultaneous removal. The EPS production by A. niger increased in the presence of these elements along with changes in the polysaccharide and protein content of the EPS. The fluorescence EEM spectra revealed that the EPS produced by A. niger during pollutant removal was mostly composed of soluble microbial products and humic acid like substances. This study demonstrated recovery of elemental chalcogen and indium chalcogenide nanoparticles can be achieved using fungal pelleted systems.

Recycling of Discarded Photovoltaic Solar Modules for Metal Recovery: A Review and Outlook for the Future

The extensive deployment of photovoltaic (PV) modules at an expeditious rate worldwide leads to a massive generation of solar waste (60–78 million tonnes by 2050). A stringent recycling effort to recover metal resources from end-of-life PVs is required for resource recovery, circular economy, and subsequent reduction of environmental impact. The recovery of metallic resources (silicon, silver, copper, lead, and tin) from the first-generation PVs and critical elements (tellurium, indium, selenium, and gallium) from second-generation PVs are mainly targeted. This review systematically discusses the recycling literature of both generations of solar cells, market value calculations, recycling preferences, global trends, and the Indian perspective. The status of PV module recycling on a commercial scale and academic research efforts are discussed. The review systematically discusses the various possible pretreatments and extraction/refining processes. The pretreatments (physical, chemical, thermal, and hybrid processes) play a decisive role in up-gradation, impurity removal, and metal recovery. The challenges include homogeneous collection, process efficiency, holistic resource recovery, and energy considerations. Toxicity characteristics of both generations, life cycle assessment studies, recycling challenges with proposed flowsheets, and a detailed future outlook are propounded to develop a holistic metal recovery approach. In comparison, crystalline Si PVs comprise the maximum economic value. One tonne of mixed PVs (first and second generation) can yield ∼9.32 kg of Cu, ∼0.30 kg of Ag, ∼33.48 kg of Si, ∼1.12 kg of Sn, ∼1.12 kg of Pb, ∼4.9 g of Cd, ∼2.5 g of Te, and ∼3.4 g of In.

Preparation and conductive properties of CaHf1−xInxO3−δ

Doped CaZrO3 oxides exhibit high proton transport number and have been used in electrochemical hydrogen sensor to measure hydrogen content in aluminum melt. Ionic radius of Hf4+ is close to that of Zr4+; thus, it is speculated that doped CaHfO3 oxides may also possess high proton transport number. In this study, CaHf1−xInxO3−δ (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25) perovskite oxides were fabricated via solid-state reaction method. Phase composition and microstructure were characterized by X-ray diffraction and field emission scanning electron microscopy. Conductivities and transport properties of CaHf1−xInxO3−δ were investigated via defect equilibria model. The result indicated that conductivities and transport properties of CaHf1−xInxO3−δ after In doping could be improved. Moreover, conductivities increased with increasing In doping content until the stoichiometric ratio of Indium element was 0.1. CaHf0.9In0.1O2.95 showed the highest total conductivities of 5.58 × 10−8 to 7.04 × 10−3 S ⋅ cm−1 at 400–800 °C. Transport properties showed that CaHf1−xInxO3−δ (x = 0.1, 0.15, 0.2, 0.25) oxides were dominated by protonic conduction under 21% O2 and 2.5% H2O atmosphere at 400–650 °C, and the proton transport numbers of CaHf1−xInxO3−δ decreased with the increase in temperature in the range of 400–800 °C. CaHf0.9In0.1O2.95 (x = 0.1) displayed a maximum proton transport number of 0.50 at 800 °C. These findings show potential application prospects of CaHf1−xInxO3−δ in electrochemical hydrogen sensor.