Solid Indium Research Articles

Vapor Composition over Solid Indium Trichloride and in ­Indium Chloride Unsaturated Vapor

AbstractThe dependence of indium trichloride saturated and unsaturated vapor pressure on temperature was studied in the range of 630–950 K by static methods using a quartz membrane zero‐manometer and taking into account the volume of its working chamber and substance mass. The thermodynamic data on the process of dissociation of dimeric molecules and sublimation of monomer and dimer from solid indium trichloride were calculated: ΔH0subl InCl3(g)298 = 155.3 ± 6.2 kJ·mol–1; ΔS0subl InCl3(g)298 = 199.5 ± 7.9 J·mol–1·K–1; ΔH0subl In2Cl6(g)298 = 159.3 ± 6.2 kJ·mol–1; ΔS0subl In2Cl6(g)298 = 207.1±3.8 J·mol–1·K–1; ΔH0dis In2Cl6(g)298 = 152.6 ± 5.5 kJ·mol–1 and ΔS0dis In2Cl6(g)298 = 171.6 ± 5.2 J·mol–1·K–1. The saturated vapor over solid indium trichloride consists mainly of a mixture of monomeric and dimeric molecules (InCl3 and In2Cl6), and the content of the latter is slightly growing with increasing temperature.

Impact of Preferential Indium Nucleation on Electrical Conductivity of Vapor–Liquid–Solid Grown Indium–Tin Oxide Nanowires

Highly conductive and transparent indium-tin oxide (ITO) single-crystalline nanowires, formed by the vapor-liquid-solid (VLS) method, hold great promise for various nanoscale device applications. However, increasing an electrical conductivity of VLS grown ITO nanowires is still a challenging issue due to the intrinsic difficulty in controlling complex material transports of the VLS process. Here, we demonstrate a crucial role of preferential indium nucleation on the electrical conductivity of VLS grown ITO nanowires using gold catalysts. In spite of the fact that the vapor pressure of tin is lower than that of indium, we found that the indium concentration within the nanowires was always higher than the nominal composition. The VLS growth of ITO through gold catalysts significantly differs from ITO film formations due to the emergence of preferential indium nucleation only at a liquid-solid interface. Furthermore, we demonstrate that the averaged resistivity of ITO nanowires can be decreased down to 2.1 × 10(-4) Ω cm, which is the lowest compared with values previously reported, via intentionally increasing the tin concentration within the nanowires.

Fabrication, structure and mechanical properties of indium nanopillars

Solid and hollow cylindrical indium pillars with nanoscale diameters were prepared using electron beam lithography followed by the electroplating fabrication method. The microstructure of the solid-core indium pillars was characterized by scanning micro-X-ray diffraction, which shows that the indium pillars were annealed at room temperature with very few dislocations remaining in the samples. The mechanical properties of the solid pillars were characterized using a uniaxial microcompression technique, which demonstrated that the engineering yield stress is ∼9 times greater than bulk and is ∼1/28 of the indium shear modulus, suggesting that the attained stresses are close to theoretical strength. Microcompression of hollow indium nanopillars showed evidence of brittle fracture. This may suggest that the failure mode for one of the most ductile metals can become brittle when the feature size is sufficiently small.

Growth of One-Dimensional Hierarchical Multilayered Indium Nanostructures

Novel one-dimensional (1D) hierarchical multilayered indium nanostructures were successfully synthesized via chemical reduction of InCl3·4H2O with Zn powder or foils in small alcohols, including methanol, ethanol, n-propyl alcohol, and the mixture of these alcohols. Electron diffraction (ED) and high-resolution transmission electronic microscopy (HRTEM) analyses revealed that the interesting multilayered nanostructures were grown from the assembly of elliptic indium monolayers along the [110] direction and the monolayer-density of the multilayered nanostructures was controllable by changing the alkyl-chain length of small alcohols. The TEM investigations for indium nanostructures obtained at different reaction stages revealed that the 1D hierarchical multilayered nanostructures gradually evolve from solid indium nanorods. On the basis of the TEM investigations and binary eutectic phase diagram of In−Zn, we proposed that the interesting evolvement of nanorods into 1D multilayered nanostructures resulted fr...

AlInN optical confinement layers for edge emitting group III‐nitride laser structures

AbstractAl1–xInxN ternary alloys with solid phase indium compositions between x = 0.15 and 0.28 have been grown by metalorganic chemical vapor deposition under indium rich conditions. Within the growth temperature range of 750‐810 °C the indium incorporation into the solid is increasingly reduced by a competing process with thermal activation energy of 1.07 eV. Using this growth scheme, smooth epitaxial layers with root mean‐squares surfaces roughness of 0.3‐0.8 nm are obtained. Extrinsic origin is suggested for the low temperature photoluminescence peak associated with these layers. (Al,In)N films lattice‐matched to GaN have been introduced into laser diode structures for optical confinement. Optical gain is observed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Intense multimicrojoule high-order harmonics generated from neutral atoms of In2O3 nanoparticles

We studied high-order harmonic generation from plasma that contains an abundance of indium oxide nanoparticles. We found that harmonics from nanoparticle-containing plasma are considerably more intense than from plasma produced on the In2O3 bulk target, with high-order harmonic energy ranging from 6 μJ (for the ninth harmonic) to 1 μJ (for the 17th harmonic) in the former case. The harmonic cutoff from nanoparticles was at the 21st order, which is lower than that observed using indium oxide solid target. By comparing the harmonic spectra obtained from solid and nanoparticle indium oxide targets, we concluded that intense harmonics in the latter case are dominantly generated from neutral atoms of the In2O3 nanoparticles.

Selective area metal-organic vapor-phase epitaxy of InN, GaN and InGaN covering whole composition range

To investigate mask effects on InGaN selective area metal-organic vapor-phase epitaxy (SA-MOVPE), in-plane thickness profiles of InGaN were investigated with various indium contents covering between InN and GaN. A numerical simulation employing vapor-phase diffusion (VPD) model was also carried out for the quantitative analysis of VPD effect. At the growth temperatures of 650 and 700 °C, the indium content in the vapor phase and that in the solid phase exhibited almost linear relationship, suggesting that the growth of InGaN can be approximated as the superposition of the growth of InN and GaN. The effective vapor-phase diffusion length D/ k s of GaN was much smaller than InN. The profile of the InGaN growth rate in the selective area became more gradual as the solid indium content increased, and the trend seems to be the linear interpolation between the profiles of GaN and InN. However, as the indium content increases, deposition selectivity between mask and crystal surface become degenerated, and the VPD effect was almost canceled when the solid indium content exceeds 0.5. Although further improvement on the growth conditions is necessary to improve selectivity, basic information for the design of the SA-MOVPE of InGaN has been obtained, which will contribute to InGaN-based monolithically integrated multi-wavelength devices.

On the internal energy of sputtered clusters

We have used laser ionization and time-of-flight mass spectrometry to investigate the internal excitation of neutral clusters that were generated by sputtering from a solid indium surface under bombardment with 15 keV Xe+ ions. More specifically, single photon ionization of the clusters is accomplished by a tunable, frequency doubled laser and the photoionization efficiency (PIE) curves are collected with the photon energy varied around the ionization energy in a range between 4.2–6 eV. The results are compared with the PIE curves of supposedly cold indium clusters which were produced by a supersonic nozzle expansion using a laser vaporization source and investigated under otherwise similar conditions. As a result, the sputtered clusters show a distinctive broadening and shift of the PIE curve in the threshold region, thus illustrating the influence of the sputtering process in increasing the internal energy of the ejected clusters. The experimental PIE curves are interpreted in terms of a simple model using the internal temperature and ionization energy of the cluster as fit parameters. Depending on the cluster size, temperatures between 3850 and about 1000 K are found for sputtered Inn clusters.

Temperature effect study on structural and morphological properties of In .08Ga .92As/GaAs structures grown by MOVPE

In .08Ga .92As layers were grown on the GaAs(0 0 1) substrate by atmospheric pressure metalorganic vapour-phase epitaxy (AP-MOVPE). Among growth conditions, only growth temperature was varied in the range 520–680 °C. This temperature interval keeps solid indium composition constant when fixing vapour indium composition. In order to improve crystal quality and to contribute to the understanding of the growth kinetic, we have studied the temperature effect on morphological and structural properties and growth process of In .08Ga .92As/GaAs structures. Surface morphology evolution of InGaAs films (RMS surface roughness, hatchings and islands of formations, densities, sizes and uniformities, etc.) and growth process (growth anisotropy, etc.) versus growth temperature were investigated by atomic force microscopy (AFM) and plan-view scanning electronic microscopy (SEM). Dislocations density and alloys disorder (by using Urbach energy) changes of InGaAs alloys were examined by high-resolution X-ray diffraction (HRXRD) in rocking curves mode and optical absorption (OA) measurements, respectively. A correlation between results and comparison with the literature has been given. All measurements show that optimal growth temperature regarding crystal quality (defects density, alloys disorder, etc.) is about 520 °C. Besides, surface morphology of In .08Ga .92As at this temperature was specified by the presence of hatchings and the absence of islands. As a manufactured diffraction grating, we find that hatchings network can diffract a 632.8 nm incident laser.

Indium incorporation dynamics into AlInN ternary alloys for laser structures lattice matched to GaN

Al 1 − x In x N ternary alloys with solid phase indium compositions between x=0.15 and 0.28 have been grown by metal organic chemical vapor deposition under indium rich conditions within the growth temperature range of 750–810 °C. A thermally activated process with activation energy of 1.05±0.05eV is found to compete with indium incorporation. Smooth epitaxial layers with root mean-squares surface roughness of 0.3–0.8nm are obtained. (Al,In)N films lattice matched to GaN have been introduced into laser diode structures for optical confinement. Optical gain is observed.

VLS growth of GaAs/(InGa)As/GaAs axial double-heterostructure nanowires by MOVPE

We report on the gold-based vapor–liquid–solid (VLS) growth of GaAs/(InGa)As/GaAs axial double-heterostructure nanowires using low-pressure metal-organic vapor phase epitaxy (MOVPE). Systematic growth investigations were performed to study the influence of the growth time, the temperature and the V/III ratio on the composition and the extent of the (InGa)As segments. A group-III precursor growth interrupt prior to and after the (InGa)As growth showed the highest solid indium fraction and the strongest composition gradients at the heterojunctions. The experimental results were discussed considering the droplet composition as well as MOVPE and VLS kinetics.

Extraction method for preparing indium-containing liquid organic scintillators for solar neutrino detection for LENS experiment, low-energy neutrino spectroscopy

Extraction of In with solutions of 2-methylvaleric acid (H2MVA) in trimethylbenzene (TMB) was studied. Depending on pH of the equilibrium aqueous phase, the extracted indium species are In(2MVA)3 · 3(H2MVA), In(2MVA)3, [In(2MVA)x(OH)3−x]n, etc., where 2MVA is the 2-methylvalerate anion and n is the degree of polymerization. By the extraction method, In-containing liquid organic scintillators (LOSs) with the following parameters were obtained: [In] = 50–96 g l−1, transparency 2–3 m, light output 68% relative to TMB. Long-term precision trials of the scintillators in the Gran Sasso underground laboratory (Italy) confirmed that the scintillator parameters were stable and met the requirements of the LENS experiment. A procedure was developed for preparing solid anhydrous indium hydroxycarboxylates, and their properties were studied. LOSs based on solutions of solid indium hydroxycarboxylates in TMB were prepared and subjected to long-term trials in which the transparency and light output were monitored. One of the major factors responsible for the instability of indium-containing LOSs is the presence of water in the organic phase.

Structural features of the electrode/solution interface at the reduction of Cr3+(aq) cations on liquid mercury and solid indium electrodes in acidic media

Characteristics of electroreduction of Cr3+ and Cr2+ ions on the dropping mercury (literature data) and indium cathodes are analyzed as a function of pH of the medium. A hypothesis that polymeric hydroxocompounds of chromium, which are present in different aggregate states, represent the main or partial reactants in the \( Cr\left( {III} \right)\xrightarrow{{ + e}}Cr\left( {II} \right)\xrightarrow{{ + 2e}}Cr \) stages is additionally substantiated.

Heat capacity of indium nitride

The heat capacity of the solid indium nitride was measured, using the Calvet TG-DSC 111 differential scanning microcalorimeter (Setaram, France), in the temperature between (314–978 K). The temperature dependence of the heat capacity can be presented in the following form: Cp=41.400+0.499·10−3T−135502T−2−26169900 T−3.

Density of indium antimonide at high temperatures

The density of solid and liquid indium antimonide was studied by irradiating the samples with a narrow beam of monochromatic gamma-radiation in the temperature range of 293–1950 K, including the range of melting — crystallization. The measurement errors for the density and thermal expansion coefficients were ±(0.25–0.40) % and ± 4 %, correspondingly. The approximating equations and tables of reference data were obtained for the temperature dependence of thermal properties. Measurement results were compared with the known published data.

Patterning of Hard Coatings for Incorporation of Solid Lubricant Microreservoirs

ABSTRACTHard coatings containing microscopic reservoirs for solid lubricant storage have the potential to advance the development of dry, self-lubricating coatings. In the present study we have investigated several methods for fabricating hard coatings that incorporate microscopic reservoirs. These methods all involve the use of placeholders on the substrate surface that are later removed after deposition of the hard coating. One method uses a solution containing ceramic beads, while the second method uses conventional photolithography methods. Coatings using both of these methods were fabricated using TiN as the hard coating. The effectiveness of the microreservoirs for solid lubricant storage was examined by conducting pin-on-disk test using various solid lubricants, including graphite and indium. The performance of coatings with random arrangements of microreservoirs was scattered while samples with the ordered arrangements of microreservoirs all performed well. Optical microscopy examination of the wear tracks showed the microreservoirs were generally successful at trapping the graphite lubricant during wear. With a sufficient density and appropriate distribution of the microreservoirs, the significant improvements in tribological performance can be realized.

Thermodynamic properties of InP

The emf of an electrochemical cell of the type (−) W, In(l) | ZnCl2 + KCl + NaCl + InCl | (InP(s) + P(black)), W(+) has been measured in the temperature range 500–600 K. The change in the chemical potential of this cell (ΔμIn=−52.50 + 19.01 × 10−3 T kJ/mol) corresponds to the reaction In(l) + P(black) → InP(s). The standard enthalpy of formation of InP from solid indium and white phosphorus is determined to be Δf H 0(298 K) = −69.3 ± 3 kJ/mol. We have performed thermodynamic analysis of the literature data for the In-P system, with consideration for different phosphorus allotropes.

InGaN quantum well epilayers morphological evolution under a wide range of MOCVD growth parameter sets

AbstractThis study exemplifies the use of TappingModeTM atomic force microscopy (AFM) surface morphology imaging to investigate and optimise the metalorganic chemical vapour deposition (MOCVD) growth conditions and post‐growth stability of thin (<40 Å) InGaN layers with direct implications to the structural and optical properties of blue (460 nm) and green (520 nm) LEDs. InGaN epilayers less than 40 Å thick of ∼20% solid phase indium were produced on thick (3‐4 µm) 2″ GaN templates grown on (0001) c ‐plane sapphire substrates. The morphological evolution of the InGaN material was studied utilising a DI3100 AFM tool. Surface morphology and its correlation with photoluminescence and X‐ray diffraction results will be discussed for every set of conditions employed. More specifically, the post‐growth ambient exposure and thermal stability of the uncapped InGaN epilayers were investigated. In addition, the initial stage of subsequent GaN growth, which is an essential step towards the manufacture of LED active regions, was examined. Based on the above findings, a flexible MOCVD growth parameter space and improved LED constituent layer sequencing techniques have been established leading to more efficient and stable LED devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Thermodynamic properties of liquid silver–indium alloys determined from e.m.f. measurements

The thermodynamic properties of the liquid Ag–In alloys were determined using solid oxide galvanic cells with zirconia electrolyte. The e.m.f.'s of the cells Re + kanthal, Ag x In (1− x) ,In 2O 3//ZrO 2 + (Y 2O 3)//NiO, Ni, Pt were measured in the temperature range from 950 to 1273 K, and in the molar fraction from x In = 0.15 to 1.0. At first, the Gibbs free energy of formation of pure solid indium oxide, In 2O 3, from pure elements was derived. Using values of the e.m.f.'s measured for the cell with x In = 1.0, the following temperature dependence was obtained: Δ f G m , In 2 O 3 0 ( ± 1000 mo l − 1 J ) = − 911570 + 313.10 T Next, the activities of indium were derived as a function of the alloy composition from measured e.m.f.'s. Activities of silver were calculated using Gibbs–Duhem equation. Also, using Darken's α-function formalism, activity coefficient of indium at infinite dilution in silver was calculated. These data taken together with the heat of mixing values which are available in the literature enabled the description of the thermodynamic properties of the liquid phase with Redlich–Kister polynomial expansion. Finally, the Ag–In phase diagram was recalculated using ThermoCalc software. The limiting value of the logarithm of the activity coefficient of indium in silver was also given as a function of temperature.

Organoindate Room Temperature Ionic Liquid: Synthesis, Physicochemical Properties and Application

The combination of equimolar amounts of solid 1-n-bu- tyl-3-methylimidazolum chloride (BMI·Cl) with solid indium trichloride affords the new room temperature and air stable ionic liquid BMI·InCl4 (mp -6 °C). The major physicochemical proper- ties (density, viscosity, electrical conductivity and electrochemical window) of BMI·InCl4 are complementary to those of classical tet- rafluoroborate or hexafluorophosphate analogues. However, this liquid possesses similar Lewis acidity properties to those of orga- noaluminate melts and can be used as recyclable media, as demon- strated here for the tetrahydropyranylation of alcohols.