Neutral Indium Research Articles

Laser cooling of an indium atomic beam enabled by magnetic fields

We demonstrate magnetic field enabled optical forces on a neutral indium atomic beam in a light field consisting of five frequencies. The role of dark magnetic ground state sublevels is studied and enables us to cool the atomic beam transversely to near the Doppler limit with laser frequencies tuned above the atomic resonance. The effect of laser cooling can be explained with transient effects in the light potential created by the standing wave light field where the atoms are optically pumped into the dark states and recycled by Larmor precession.

Ab-initio study on parameter extraction for kinetic Monte Carlo simulation of neutral indium diffusion in uniaxially- and biaxially-strained silicon

In this paper, we present our ab-initio study on energy configurations, minimum energy path (MEP), and migration energy for neutral indium diffusion in a uniaxial and biaxial tensile strained {100} silicon layer. Our ab-initio calculation of the electronic structure allowed us to figure out transient atomistic configurations during the indium diffusion in strained silicon. We found that the lowest-energy structure (InS-SiiTd) consists of indium sitting on a substitutional site while stabilizing a silicon self-interstitial in a nearby tetrahedral position. Our ab-initio calculation revealed that the next lowest-energy structure is IniTd, the interstitial indium at the tetrahedral position. We employed the nudged elastic band (NEB) method for estimating the MEP between the two structural states. The NEB method teaches us that the diffusion pathway of neutral indium is kept unchanged in strained silicon while the migration energy of indium fluctuates in strained silicon.

“Dissolution” of Indium(I) Iodide: Synthesis and Structural Characterization of the Neutral Indium Sub‐Halide Cluster Complex [In6I8(tmeda)4

“Dissolution” of Indium(I) Iodide: Synthesis and Structural Characterization of the Neutral Indium Sub‐Halide Cluster Complex [In₆I₈(tmeda)₄

Ab Initio Study with Transition State Theory (TST) for the Calculation of the Barrier Height of Migration Energy of Neutral Indium in Silicon

In this paper, we present ab-initio study on the energy configurations, minimum energy path (MEP), and migration energy of neutral indium atom during diffusion in silicon crystal. From the ab-initio calculation of electronic structure, we could figure out the transient atomistic configurations during the indium diffusion in silicon. We found that the lowest-energy structure (Ins + Sii Td) consists of indium sitting on a substitutional site for stabilizing a silicon self-interstitial in a nearby tetrahedral position. The second lowest-energy structure was found to be Ini Td, the interstitial indium at the tetrahedral position. We employed the climbing image nudged elastic band (CINEB) method for estimating the MEP between the two local energy minima and the migration energy of the neutral indium, and obtained the MEP of 0.79 eV.

Proton conduction in indium hydrogensulfate and hydrous zirconia composites

Solid composite proton electrolytes based on indium hydrogensulfate and hydrous zirconia are studied. A composite effect is observed in these systems: their proton conductivity is higher than in the starting components. Maximal conductivities are achieved at a comparatively low concentration of hydrous zirconia (10% wt %) in composites heat-treated at 373 K. The increasing surface basicity of hydrous zirconia as a result changing its deposition pH noticeably improves the low-temperature conductivity of the composites. Irreversible processes that decrease the conductivity occur in composites even during treatment at temperatures above 373 K. A third component (neutral indium sulfate) only decreases the conductivity.

Resist-assisted atom lithography with group III elements

Resist-assisted atom lithography with group III elements, specifically with gallium and indium, is demonstrated. Self-assembled monolayers (SAM) of nonanethiols prepared on thin sputtered gold films were exposed to a beam of neutral gallium and indium atoms through a physical mask. The interaction of the Ga and In atoms with the nonanethiol layer, followed by a wet etching process, creates well defined structures on the gold film, with features below 100 nm. The threshold of the lithographic process was estimated by optical methods and found to be around 3 gallium atoms and 12 indium atoms per thiol molecule. Our experiments suggest that resist-assisted atom lithography can be realized with group III elements and possibly extended to new neutral atomic species.

Modeling of indium diffusion and end-of-range defects in silicon using a kinetic Monte Carlo simulation

We describe in this article atomistic modeling of transient enhanced diffusion of indium and end-of-range defects in silicon using a kinetic Monte Carlo (KMC) simulation technique. All types of defects, including small point defect clusters, {311} defects, dislocation loops, and voids are taken into account during the random walk of indium in silicon. Neutral point defect-mediated indium migration, which includes both indium-interstitial and indium-vacancy pairs, is implemented in the KMC diffusion simulator. Indium diffusion simulation after a subamorphous implant dose (In 200 keV, 1×1013/cm2) could be fully explained by indium-interstitial pair migration with reasonable activation energy and the Frank–Turnbull mechanism was not dominant. In the case of an amorphous implant dose (In 200 keV, 1×1014/cm2), the KMC simulation shows small {311} defects at the initial stage of annealing that nucleate into dislocation loops. Atomistic KMC simulation also confirms that it is primarily interstitial clusters, {311} defects, and loops that play the most important roles in indium diffusion above the amorphous implant dose.

A theoretical study of structural, vibrational, and electronic properties of neutral, positive, and negative indium arsenide clusters, [formula omitted

First principles study of the small InAs n clusters is performed to investigate the changes in structural, vibrational and electronic properties, when an electron is either added or removed from the corresponding neutral clusters. The calculated results reveal that the addition of an electron to the neutral clusters induce significant structural changes relative to the case when an electron is removed. The changes in vibrational properties can be explained in terms of the variation of the interatomic distances upon removing or adding the electron. The calculated values of electron affinity and ionization potential are comparable to those calculated in GaAs and InP clusters.

Internal excitation of sputtered neutral indium clusters

The internal energy distribution of neutral indium clusters In n sputtered from a polycrystalline In surface by 15 keV Xe + ions is investigated by means of laser post-ionization and time-of-flight mass spectrometry. In particular, the neutral species are ionized by a tunable frequency doubled dye-laser and the photoionization efficiency (PIE) curves were collected with the photon energy varied around the ionization potential. This way, internal energy distributions of sputtered clusters in the size range n=2–35 could be determined using photon energies of 4.2–6 eV. The results are compared with the PIE curves of 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 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.

Identification of charge states of indium vacancies in InP using the positron-electron auto-correlation function

The positron-electron auto-correlation function (ACF) is calculated for neutral and negatively charged indium vacancies in InP as well as a perfect InP material. Ab initio calculations are performed for the electron wave functions in the density functional theory (DFT) with the local density approximation (LDA) for the exchange-correlation potential of electrons. The positron wave function is calculated by directly diagonalizing the single-particle Hamiltonian of the positron in the LDA with a density-gradient correction. It is found that the ACF is suitable for identifying the charge states of the indium vacancies. Neutral indium vacancies greatly diminish the nearest peaks and dips (P1 and D1) of the ACF which are located after the nearest-neighbouring lattice points in the case of a perfect material. Negatively charged indium vacancies nearly eliminate these peaks and dips, together with the next-nearest peaks (P2) located at the next-nearest-neighbouring lattice points. Therefore, the diminution of the P1 and D1 can be taken as an indication of the formation of neutral indium vacancies, and that of the P2 can be taken as an indication of the formation of negatively charged indium vacancies. However, the three negative charge states of the indium vacancies ( and ) are still difficult to distinguish from each other by means of the ACF method.

Synthesis and structural characterization of the neutral indium (III) thiolate species In{(SCH 2CH 2) 3N}

The neutral indium(III) thiolate species In{(SCH 2CH 2) 3N} was synthesized and structurally characterized.

Organic‐Soluble Neutral and Ionic Indium Siloxane Cages: Potential Precursors for Indium‐Containing Silicates

Small variations in the reaction conditions and the choice of starting materials lead to a diverse range of novel indium siloxane structures. These compounds can serve as model compounds for zeolites. The framework of one of the indium siloxanes is depicted on the right.

Neutral five-coordinate gallium(III) and indium(III) complexes from sulphur ligands

Neutral five-coordinate gallium(III) and indium(III) complexes from sulphur ligands

Intramolekular-stabilisierte Organogallium-und -indiumhalogenide. Ein erstes neutrales Indiumhydrid

Abstract The intramolecularly coordinating 2-(dimethylaminomethyl)phenyl-(X) and 4-terr-butyl-2,6-bis(dimethylaminomethyl)phenyl-(Y) ligands were employed in the preparation of the gallium and indium halides: X2InI (B), XInI2 (1), X2InBr (2), XInBr2 (3), XIn(Et)I (4), XGaI2 (6) and YInI2 (7). The first neutral indium hydride X2InH (5) was made in situ from LiInH4 and 2. Z2InCl (8) (Z = 2-pyridyl-bis(trimethylsilyl)methyl), and X3Ga (C) were also synthesized. The compounds are characterized by N. M. R. (1H, 13C, 29Si and for 6 71Ga) and mass spectrometry and elemental analyses or peak matching M. S.. N. M. R.-data are discussed as well as the X-ray structure analyses provided for B, 2, 4, 5, 7 and 8.

Kinetic energy distributions of sputtered indium atoms and clusters

The kinetic energy distributions of neutral indium atoms and clusters through In 8 were measured during the sputtering of a polycrystalline indium surface by normally incident ∼ 4 keV Ar + ions using laser post-ionization in combination with time-of-flight mass spectrometry. Data on In 8 clusters represent the largest and heaviest sputtered neutral cluster for which kinetic energy distribution data are available. The slopes of the high energy tails for the various cluster kinetic energy distributions are nearly equal to each other and to the values found for copper and aluminum cluster distributions previously measured in this laboratory. The energies at which the distributions reach a maximum decrease from a value of 1.6 eV for In atoms to a value of 1.1 eV for In 8. The possible influence of photofragmentation and unimolecular fragmentation on the kinetic energy distributions was investigated and found not to significantly affect the measurements.

Sputtering of neutral and ionic indium clusters

Secondary neutral and secondary ion cluster yields were measured during the sputtering of a polycrystalline indium surface by normally incident ∼4 keV Ar+ ions. In the secondary neutral mass spectra, indium clusters as large as In32 were observed. In the secondary ion mass spectra, indium clusters up to In18+ were recorded. Cluster yields obtained from both the neutral and ion channel exhibited a power law dependence on the number of constituent atoms n in the cluster, with the exponents measured to be −5.6 and −4.1, respectively. An abundance drop was observed at n=8, 15, and 16 in both the neutral and ion yield distributions, suggesting that the stability of the ion (either secondary ion or photoion) plays a significant role in the observed distributions. In addition, our experiments suggest that unimolecular decomposition of the neutral cluster may also play an important role in the measured yield distributions.

Synthesis and characterization of the monomeric three-coordinate indium thiolate and selenolate complexes In[E(2,4,6-tert-Bu3C6H2)]3 (E = S, Se)

The synthesis and characterization of the monomeric neutral three-coordinate indium thiolate and selenolate derivatives In[S(2,4,6-t-Bu 3 C 6 H 2 )] 3 (1) and In[Se(2,4,6-t-Bu 3 C 6 H 2 )] 3 .2PhMe (2) are described. Compound 1 was synthesized by the reaction of In[N(SiMe 3 ) 2 ] 3 with 3 equiv of HS(2,4,6-t-Bu 3 C 6 H 2 ) in toluene whereas 2 was obtained by the reaction of InEt 3 with 3 equiv of HSe(2,4,6-t-Bu 3 C 6 H 2 ) in the same solvent

Shell structure of small indium clusters below N≈200 atoms

Neutral indium cluster In N ( N≤200) are laser photoionized near threshold and analyzed by time-of-flight mass spectrometry. Strong shell effects are observed in cluster mass spectra. For In N clusters below N=125, individual ionization potentials are deduced. They are compared with theoretical predictions calculated within the framework of the spherical-jellium model. The agreement is qualitatively quite good and the observed shell effects correspond to the successive major electronic shell closures. Deviations from electronic shell model predictions are much less important for indium clusters than for aluminum ones. A tentative explanation of this difference is given.

Optical and near-infrared spectroscopy of neutral indium phosphide clusters

Spectra are obtained for a wide distribution of sizes and stoichiometries of indium phosphide clusters using photodissociation techniques. These spectra are presented at two different cluster temperatures throughout the spectral range of 0.65 eV (1900 nm) to 2.0 eV (640 nm) for indium phosphide clusters containing from 5 to 14 atoms. Though the spectral behaviors of the clusters are found to be qualitatively similar, significant quantitative differences exist. A Rice–Ramsberger–Kassel–Marcus (RRKM) dissociation model employing significant fitting constraints is found to accurately describe the observed dissociation behaviors at both temperatures. Dissociation energies ranging from 2.0 to 2.4 eV are determined for the In5Py–In9Py clusters using the RRKM model. Experimental evidence suggests that the dissociation process involves loss of a small phosphorus containing moiety such as P1–2 or InP1–2. Results of the RRKM fitting process also clearly indicate that most of these InxPy clusters have nearly uniform absorption cross sections from 0.65 to 2.0 eV. This range extends well below the band gap of bulk InP. This is the first clear evidence of the presence of electronic states in closed shell semiconductor clusters at energies well below the band gap of the bulk material. Select clusters show significant deviations from pure RRKM behavior. Their behavior is consistent with the presence of spectral structure in their absorption cross sections in the energy range of 0.65–2.0 eV.

Newly observed lines and hyperfine structure in the infrared spectrum of indium obtained by using a Fourier-transform spectrometer

The spectrum of neutral indium has been studied in the infrared region by means of the Fourier-transform spectrometer at the Laboratoire Aime Cotton, Orsay, France. A microwave-excited discharge tube containing indium iodide was used as the light source. A total of ten hyperfine structures was studied. Precise measurements of the center of gravity of the structures give energy levels with an error less than 0.005 cm−1. Complete analysis of these hyperfine structures resulted in the determination of the magnetic-dipole and electric-quadrupole interaction constants for one odd and four even levels. The observation also resulted in the measurements of 57 lines in the region of 0.86–4.0 μm, and, of these, 41 lines were observed for the first time to our knowledge.