Showing papers on "Ion published in 1993"
TL;DR: A set of 61 ion polarizabilities has been derived from the dielectric constants of 129 oxides and 25 fluorides using a least squares refinement technique in conjunction with the Clausius-Mosotti equation as mentioned in this paper.
Abstract: A set of 61 ion polarizabilities has been derived from the dielectric constants of 129 oxides and 25 fluorides using a least squares refinement technique in conjunction with the Clausius–Mosotti equation. These polarizabilities can be used to estimate mean dielectric constants of ‘‘well‐behaved’’ compounds. They should be particularly useful in calculation of mean dielectric constants of compounds whose dielectric constants have not been determined. They can also be used as a framework for distinguishing unusual dielectric behavior from normal dielectric behavior where deviations can frequently be attributed to piezo‐ or ferroelectricity, conductivity (ionic or electronic), ‘‘rattling’’ or ‘‘compressed’’ cations with correspondingly high or low polarizabilities, or the presence of dipolar impurities. Deviations observed from calculated dielectric constants can be used to search for unusual physical behavior.
2,146 citations
TL;DR: In this paper, the polycrystalline lithium lanthanum titanate Li0.34(1)La0.5O4.94(2) showed high ionic conductivity more than 2 × 10−5 S cm−1 (D.C.A.
1,304 citations
TL;DR: The ion exchange reaction of interlayer Na+ ions of a layered polysilicate kanemite with alkyltrimetnylammonium ions, followed by calcination, gives highly ordered mesoporous materials with a hexagonal array of uniform channels as mentioned in this paper.
Abstract: The ion exchange reaction of interlayer Na+ ions of a layered polysilicate kanemite with alkyltrimetnylammonium ions, followed by calcination, gives highly ordered mesoporous materials with a hexagonal array of uniform channels.
1,091 citations
01 Jan 1993
TL;DR: In this paper, the authors present the experimental status of solid state ionics (SSI), and discuss the major contributions of SSI to technology in the past, present and future.
Abstract: Preface. 1. New routes in the development of chemical sensors: surface devices S. Pizzini. 2. Materials and concepts for solid state electrochemical devices W. Weppner. 3. Optical properties of transition-metal and rare earth ions in beta aluminas G. Mariotto. 4. Intercalation compounds M.S. Whittingham. 5. Polymer electrolytes and intercalation electrodes: fundamentals and applications P.G. Bruce. 6. Is there a future for lithium-batteries as high energy density source in electrical engine vehicles? Some recent trends C. Delmas, I. Saadoune, H. Auradou, M. Menetrier, P. Hagenmuller. 7. Ion mobility in chalcogenide semiconductors Room temperature creation of bipolar junction transistor D. Cahen, L. Chernyak, G. Dagan, A. Jakubowicz. 8. Mixed conductors for negative electrodes R.A. Huggins. 9. Surface oxygen exchange kinetics of solid oxide ion condutors B.A. Boukamp, I.C. Vinke, K.J. De Vries, A.J. Burggraaf. 10. Ionic conduction in sulphates A. Lunden. 11. Copper solid electrolyte-copper(I) halide and alkali halide systems O. Yamamoto. 12. Ionic conduction in glasses A. Magistris. 13. Chemical vapor deposition techniques for thin films of solid electrolytes and electrodes V.E.J. van Dieten, J.P. Dekker, A.A. van Zomeren, J. Schoonman. 14. Silver solid state energy storage devices B.B. Owens. 15. Bismuth-based oxide conductors novel structural and electrical features G. Mairesse. 16. Anisotropy in the ionic conductivity of K3NdSi3O8(OH)2 S.M. Hale, J. Maier, B.J. Wuensch, R.A. Laudise. 17. Peculiarities in the low temperature ion and electron conductivity of solid oxide eletrolytes H. Nafe. 18. Chemical analysis and structural investigations of sodium and lanthanide ion-exchanged beta-aluminas F. Tietz, W. Urland. 19. Electrical releaxation in polymer electrolytes I. Albinsson, B.-E. Mellander. 20. Quadrupole-broadened NMR-MAS spectra of disordered materials: acquisition and analysis P. Mustarelli. 21. Experimental working group report: What is the experimental status of solid state ionics (SSI)? R.J. Nowak, E. Zanghellini, H. Nafe, V. van Dieten. 22. Experimental working group report: What are the major contributions of solid state ionics to technology in the past and future? J.S. Lunsgaard, C. Arbizzani, M. Gina, T. Kawada, J. Lane. Final remarks W. van Gool.
1,075 citations
TL;DR: Data are found to support deposition models in which the highly tetrahedrally bonded form on nonhydrogenated amorphous carbon arises from the subplantation of incident ions, giving rise to a quenched increase in density and strain.
Abstract: A highly tetrahedrally bonded form on nonhydrogenated amorphous carbon (a-C) is produced by deposition from filtered medium-energy ion beams. A range of such films was grown and the ${\mathit{sp}}^{3}$-bonded fractions, plasmon energies, compressive stresses, and resistivities were measured as a function of ion energy. These properties are found to be strongly correlated and each to pass through a maximum at an ion energy of about 140 eV. The optimum ion energy is observed to depend on the type of carbon ions deposited and, possibly, on the deposition flux rate. The data are found to support deposition models in which the ${\mathit{sp}}^{3}$ bonding arises from the subplantation of incident ions, giving rise to a quenched increase in density and strain.
793 citations
TL;DR: In this paper, a simple model was proposed to explain the formation of compressive stress in thin films deposited with simultaneous bombardment by energetic ions or atoms, and it was shown that the stress σ is proportional to [ Y (1-v) ]E 1 2 (R j+kE 5 3 ), where E is the ion energy, R the net depositing flux, j the bombarding flux, k a material dependent parameter, Y the film material Young's modulus and v the Poisson ratio.
728 citations
TL;DR: A systematic series of single amino-acid substitutions is carried out and all four glutamates participate in high-affinity binding of Ca2+ or Cdd2+.
Abstract: VOLTAGE-GATED Ca2+ channels link changes in membrane potential to the delivery of Ca2+, a key second messenger for many cellular responses1. Ca2+ channels show selectivity for Ca2+ over more plentiful ions such as Na+ or K+ by virtue of their high-affinity binding of Ca2+ within the pore2& ndash;6. It has been suggested that this binding involves four conserved glutamate residues7& ndash;10 in equivalent positions in the putative pore-lining regions of repeats I& ndash;IV in the Ca2+ channel & alpha;1 subunit. We have carried out a systematic series of single amino-acid substitutions in each of these positions and find that all four glutamates participate in high-affinity binding of Ca2+ or Cdd2+. Each glutamate carboxylate makes a distinct contribution to ion binding, with the carboxylate in repeat III having the strongest effect. Some single glutamate-to-lysine mutations completely abolish micromolar Ca2+ block, indicating that the pore does not possess any high-affinity binding site that acts independently of the four glutamate residues. The prevailing model of Ca2+permeation2,3 must thus be modified to allow binding of two Ca2+ ions in close proximity11,12, within the sphere of influence of the four glutamates. The functional inequality of the glutamates may be advantageous in allowing simultaneous interactions with multiple Ca2+ ions moving single-file within the pore. Competition among Ca2+ ions for individual glutamates11,12, together with repulsive ion-ion electrostatic interaction2,3, may help achieve rapid flux rates through the channel2& ndash;5.
601 citations
TL;DR: The cation-pi interaction may be responsible for the ion selectivity in potassium channels, given that several conserved aromatic residues are present in the pore region of such channels.
Abstract: A combination of computational methods has been used to evaluate the interaction between the pi face of a benzene molecule and the monovalent cations of lithium, sodium, potassium, and rubidium. In the gas phase, the ions are strongly bound, and the affinity for benzene follows the expected electrostatic trend (lithium, largest; rubidium, smallest). However, in an aqueous environment, a reordering occurs such that the potassium ion is preferred over all the other ions for 2:1 benzene:ion complexes. The selectivity sequence parallels that seen in voltage-gated potassium channels. Given that several conserved aromatic residues are present in the pore region of such channels, these results suggest that the cation-pi interaction may be responsible for the ion selectivity in potassium channels.
585 citations
TL;DR: The field of low-energy ion scattering for surface interactions at metals, alloys, catalysts and semiconductors is reviewed in this article, where the basic principles, classical scattering theory, the effect of shadowing and blocking, and some of the computer simulation programs are briefly described.
531 citations
TL;DR: In the experiments described here, a single ion or a few identical ions were prepared in well-defined superpositions of two internal energy eigenstates, and the populations of the energy levels were measured.
Abstract: Measurements of internal energy states of atomic ions confined in traps can be used to illustrate fundamental properties of quantum systems, because long relaxation times and observation times are available. In the experiments described here, a single ion or a few identical ions were prepared in well-defined superpositions of two internal energy eigenstates. The populations of the energy levels were then measured. For an individual ion, the outcome of the measurement is uncertain, unless the amplitude for one of the two eigenstates is zero, and is completely uncertain when the magnitudes of the two amplitudes are equal. In one experiment, a single $^{199}\mathrm{Hg}^{+}$ ion, confined in a linear rf trap, was prepared in various superpositions of two hyperfine states. In another experiment, groups of $^{9}\mathrm{Be}^{+}$ ions, ranging in size from about 5 to about 400 ions, were confined in a Penning trap and prepared in various superposition states. The measured population fluctuations were greater when the state amplitudes were equal than when one of the amplitudes was nearly zero, in agreement with the predictions of quantum mechanics. These fluctuations, which we call quantum projection noise, are the fundamental source of noise for population measurements with a fixed number of atoms. These fluctuations are of practical importance, since they contribute to the errors of atomic frequency standards.
525 citations
TL;DR: Anicich and Huntress as mentioned in this paper evaluated the reaction rate coefficients and product distributions for bimolecular positive ion-molecule reactions of importance in planetary atmospheres, cometary comae, and interstellar clouds.
Abstract: Recommendations of reaction rate coefficients and product distributions for bimolecular positive ion‐molecule reactions of importance in planetary atmospheres, cometary comae, and interstellar clouds are presented. Two publications Anicich and Huntress, 1986, Ap. J. Supplement Series 62, 553 and Anicich, 1993, Ap. J. Supplement Series 84, 215 served as the basis for this evaluation, which covers the literature from 1965 through 1991 with some additional citations missed in the original surveys.
TL;DR: In this article, the drift-spectra of the ions from a homological series of tertiary amines are presented as well as the results of mass spectrometric identification of the various ions representing the separate peaks in the mobility spectra.
TL;DR: The dependence of mass-analyzed ion intensity I A and I B of analytes A + and B +, whose concentration in the electrosprayed methanol solution was [A + ] and [B + ], was determined in a series of experiments and for a variety of concentrations as mentioned in this paper.
Abstract: The dependence of the mass-analyzed ion intensity I A and I B of analytes A + and B + , whose concentration in the electrosprayed methanol solution was [A + ] and [B + ], was determined in a series of experiments and for a variety of concentrations. A proposed equation relating I A and I B to [As+] and [B + ] (see eq 4) was found to provide useful predictions. Coefficients k for the ions Li + , Na + , K + , Cs + , and NH 4 + and several protonated alkaloids, (ethyl) 4 N + , (n-propyl) 4 N + , (n-butyl) 4 N + , n-C 7 H 15 -NH 3+ , and nc-C 11 H 23 NH 3 + , were obtained
TL;DR: The correlation energies for 3- to 10-electron atomic ions are recomputed using more recent experimental and theoretical data and the correlation energies obtained from some density-functional models are also compared to these correlation energy data.
Abstract: Recently Davidson [ital et] [ital al]. [Phys. Rev. A 44, 7071 (1991)] have estimated nonrelativistic correlation energies and relativistic corrections to ionization potentials for atomic ions with up to 10 electrons. In this work, this approach is extended to atomic ions with 11 to 18 electrons. The correlation energies for 3- to 10-electron atomic ions are also recomputed using more recent experimental and theoretical data. Unlike other work the method focuses on the correlation contribution to the individual ionization energies which are obtained by comparing experimental data with relativistic complete-valence-space energies. [ital Ab] [ital initio] estimates of correlation contributions to the ionization energies with extensive configuration-interaction calculations of 3- to 10-electron atomic ions with nuclear charge from 4 through 10 and 18, 36, 50, 72, 100, and 144 have been obtained. The correlation energies obtained from some density-functional models are also compared to these correlation energy data.
TL;DR: The novel features of the present treatment are particularly relevant to the unique ability of electrospray ionization to transform large molecules in solution to free ions in the gas phase, with extensive multiple charging.
Book•
01 Jan 1993
TL;DR: The drift of Electrons and Ions in Gases can be traced back to the drift chamber of drift-chamber gas as mentioned in this paper, where charged particles and ions drift through the gas.
Abstract: Gas Ionization by Charged Particles and by Laser Rays.- The Drift of Electrons and Ions in Gases.- Electrostatics of Tubes, Wire Grids and Field Cages.- Amplification of Ionization.- Creation of the Signal.- Electronics for Drift Chambers.- Coordinate Measurement and Fundamental Limits of Accuracy.- Geometrical Track Parameters and their Errors.- Ion Gates.- Particle Identification by Measurement of Ionization.- Existing Drift Chambers #x2013 An Overview.- Drift-Chamber Gases.
TL;DR: In this paper, it is proposed that the sp3 bonding arises from an increased density, owing to carbon ions entering subsurface atomic sites, and an optimum ion energy arises from a balance between the incident carbon ions having sufficient energy to penetrate the surface atomic layer, while minimizing any excess energy dissipated in a thermal spike.
TL;DR: In this paper, a relatively new atmospheric pressure selected ion chemical ionization mass spectrometric technique was used to measure gas phase sulfuric and methane sulfonic acid (MSA) at two field sites.
Abstract: Measurements of gas phase sulfuric and methane sulfonic acid (MSA) have been performed using a relatively new atmospheric pressure selected ion chemical ionization mass spectrometric technique at two field sites. Both gas phase acids are photooxidation products, and their concentrations are seen to qualitatively follow solar flux. While sulfuric acid concentrations typically decline in conjunction with declining solar radiation, they sometimes level off in the mid 105–106 molecules cm−3 range after dark, even in relatively clean air. The reason for this quasi-stable nighttime sulfuric acid concentration is not well understood but may be a result of a steady state exchange of sulfuric acid between particles and the gas phase.
Measurements of OH, H2SO4, and SO2 concentrations in conjunction with aerosol number and size distribution also made possible the independent calculation of gas phase sulfuric acid production and loss rates. Calculated production and loss rates are seen to agree well in relatively clean air during the daylight hours. At night, however, the sulfuric acid concentrations and its calculated loss rate often have a nonzero value. In more polluted air masses, calculated gas phase sulfuric acid losses significantly exceed calculated production if H2SO4/aerosol reaction probabilities of 1.0 or 0.5 are assumed.
TL;DR: In this paper, lead diffusion has been measured in natural titanite using two different methods to introduce the diffusant: implantation of Pb ions and immersion of the crystals in a PbS powder reservoir.
TL;DR: In this article, it was demonstrated that sub-micrometer focused ion beams can be produced with current densities greater than 1 A ǫ cm−2 using a liquid-metal ion source.
Abstract: The technology of high‐resolution focused ion beams has advanced dramatically in the past 15 years as focusing systems have evolved from laboratory instruments producing minuscule current densities to high current density tools which have sparked an important new process: direct micromachining at the micrometer level. This development has been due primarily to the exploitation of field emission ion sources and in particular the liquid‐metal ion source. Originally developed in the early 1960’s as a byproduct of the development of electrostatic rocket engines, the liquid‐metal ion source was adapted for focused beam work in the late 1970’s, when it was demonstrated that submicrometer focused ion beams could be produced with current densities greater than 1 A cm−2. Ions can be produced with liquid‐metal ion sources from elements including Al, As, Au, B, Be, Bi, Cs, Cu, Ga, Ge, Fe, In, Li, P, Pb, Pd, Si, Sn, and Zn. In the past decade, focused ion beam systems with liquid‐metal ion sources have had a signific...
TL;DR: In this paper, the authors describe the physical architecture and performance of a quantitative three-dimensional atom probe recently constructed using a 10×10 anode array placed behind a two microchannel plate assembly in a chevron arrangement.
Abstract: The physical architecture and the performance of a quantitative three‐dimensional atom probe recently constructed are described. The development of such an instrument relies on the design of a multi‐impact position sensitive detector. The multidetection system that we have developed is based on the use of a 10×10 anode array placed behind a two microchannel plate assembly in a chevron arrangement. The spread of charge between the microchannel plate and the multianode is used to derive the position of ion striking the detector. Spatial coordinates can be calculated for multiple and simultaneous time‐of‐flight events. The procedure used for the derivation of ion positions from charge measurements is given. Specific experiments were carried out in order to determine the intrinsic spatial resolution of the multidetector. Three‐dimensional reconstruction of two‐phase materials are provided and illustrate the performance of this new apparatus. The reconstructed images demonstrate that atoms are positioned with a precision of a few tenths of a nanometer. The mass resolution M/ΔM (FWHM) of the apparatus is close to 200.
TL;DR: The structural and dynamic properties of protein ions in vacuo have been probed by hydrogen-deuterium exchange in a Fourier-transform mass spectrometer to provide further insight into the role of solvent in protein conformer stabilization.
Abstract: For further insight into the role of solvent in protein conformer stabilization, the structural and dynamic properties of protein ions in vacuo have been probed by hydrogen-deuterium exchange in a Fourier-transform mass spectrometer. Multiply charged ions generated by electrospray ionization of five proteins show exchange reactions with 2H2O at 10(-7) torr (1 torr = 133.3 Pa) exhibiting pseudo-first-order kinetics. Gas-phase compactness of the S-S cross-linked RNase A relative to denatured S-derivatized RNase A is indicated by exchange of 35 and 135 hydrogen atoms, respectively. For pure cytochrome c ions, the existence of at least three distinct gaseous conformers is indicated by the substantially different values--52, 113, and 74--of reactive H atoms; the observation of these same values for ions of a number--2, 7, and 5, respectively--of different charge states indicates conformational insensitivity to coulombic forces. For each of these conformers, the compactness in vacuo indicated by these values corresponds directly to that of a known conformer structure in the solution from which the conformer ions are produced by electrospray. S-derivatized RNase A ions also exist as at least two gaseous conformers exchanging 50-140 H atoms. Gaseous conformer ions are isometrically stable for hours; removal of solvent greatly increases conformational rigidity. More specific ion-molecule reactions could provide further details of conformer structures.
TL;DR: The current theories of the physics of nonaqueous electrolyte solutions and dispersions are reviewed in this article in the form of discussions of twenty-two related topics, including the influence of water on the creation and stabilization of electrical charges.
TL;DR: In this article, the theoretical background to the optical basicity concept is described, which is based on orbital expansion effects reflecting the nature of the chemical bonding between a Lewis acid-base pair.
TL;DR: Using calculations of clusters, involving more than one TM ion, the double peaked main line of the Ni 2p spectrum of NiO is explained as well as the difference in line shape compared with Ni impurities in MgO and the sensitivity of the line shape in NiO to surrounding defects.
Abstract: We show that the 2p core-level line shapes of transition metal (TM) compounds are strongly influenced by the presence of more TM ions. Using calculations of clusters, involving more than one TM ion we explain the double peaked main line of the Ni 2p spectrum of NiO as well as the difference in line shape compared with Ni impurities in MgO and show the sensitivity of the line shape in NiO to surrounding defects. This intersite charge transfer screening also explains the wide asymmetric shape of the main line of the Cu 2p spectrum of CuO and the high-${\mathit{T}}_{\mathit{c}}$ compounds.
TL;DR: In this paper, the binding properties of specific designed receptors are described with emphasis on the binding strength and the structures of the complexes, and a brief review is concluded by a brief survey of them.
Abstract: This paper describes binding properties of specifically designed receptors. Anion binding ligands use a large variety of binding sites (ammonium, guanidinium, Lewis acid m); all these classes will be presented with emphasis on the binding strength and the structures of the complexes. The review is concluded by a brief survey of
TL;DR: Ion chromatography was used to determine the structure of pure carbon cluster ions as a function of size from C4 to C84, and results indicate that carbon grows first in linear chains, transforms to monocyclic planar rings at about C10, and forms new families of planar bi-, tri-, and tetracyclic rings at C20, C30, and C40.
Abstract: Gas-phase ion chromatography can separate ions that have the same mass but differ in isomeric structure or electronic configuration. The main features of this technique are briefly outlined, and applications to a series of problems in transition metal chemistry and carbon cluster chemistry are described. Examples in transition metal chemistry include state-selective reactivity, excited state deactivation, and state-selective ligand binding energies. For clusters, ion chromatography was used to determine the structure of pure carbon cluster ions as a function of size from C4 to C84. The results indicate that carbon grows first in linear chains, transforms to monocyclic planar rings at about C10, and forms new families of planar bi-, tri-, and tetracyclic rings at C20, C30, and C40, respectively. Fullerenes, which mysteriously appear at C30 and dominate by C50, are generated by heating the planar ring systems above an isomerization barrier rather than by growth of graphite precursors.
TL;DR: Precision, accuracy and mass resolution of fragment ions were almost as good as obtained in high-energy collisionally activated dissociation (CAD) studies performed in four-sector instruments and instrumental sensitivity was better by at least one order of magnitude.
Abstract: In matrix-assisted laser desorption ionization (MALDI) a large fraction of analyte ions undergo post-source decay (PSD) during flight in the field-free drift path. By means of a modified two-stage reflectron, product ion time-of-flight spectra of medium-sized linear peptides (up to 2800 u) were recorded, containing full sequence information. Precision, accuracy and mass resolution of fragment ions were almost as good as obtained in high-energy collisionally activated dissociation (CAD) studies performed in four-sector instruments. Instrumental sensitivity was better by at least one order of magnitude. In reflectron time-of-flight mass spectrometry (RETOF-MS) the cleavage pattern of PSD products is different from that obtained by high-energy and low-energy CAD. Activation mechanisms of PSD were found to be largely determined by collisional events (ion/neutral) occurring in the acceleration field during early plume expansion. Future potentials of PSD analysis after MALDI are discussed.
TL;DR: In this paper, a four-grid electrostatic energy analyzer for measurements of the ion velocity distribution and the emission of secondary electrons on the electrodes of low-pressure radio frequency glow discharge systems has been conceived.
Abstract: A four‐grid electrostatic energy analyzer for measurements of the ion velocity distribution and the emission of secondary electrons on the electrodes of low‐pressure radio frequency glow‐discharge systems has been conceived. Problems arising from poor analyzer design are discussed and the performance of the presented analyzer is shown for measurements of the ion velocity distribution in pure hydrogen, helium, and argon discharges. Moreover, the secondary electron yields on aluminium, stainless steel, copper, and amorphous silicon exposed to radio frequency argon, helium, and hydrogen plasmas are determined in situ, for the first time to our knowledge. In parallel‐plate radio frequency discharges secondary electron emission involves the contributions of ions, fast neutrals, metastables, and photons impinging on the electrode surfaces. Therefore, secondary electron emission must be considered as a global phenomenon. Global secondary electron emission can be up to ten times larger than only ion‐induced secon...
TL;DR: In this paper, the rotational and vibrational states of the translational energy of D2(v,J) formed in recombinative desorption from Cu(111) were investigated.
Abstract: We have investigated the dependence on the rotational and vibrational states of the translational energy of D2(v,J) formed in recombinative desorption from Cu(111). These results provide information about the effect of rotational energy relative to that of vibrational and translational energy on the dissociative chemisorption of D2 on Cu(111). The range of rovibrational states measured includes rotational states J=0–14 for vibrational state v=0, J=0–12 for v=1, and J=0–8 for v=2. D2 molecules were detected in a quantum‐state‐specific manner using three‐photon resonance‐enhanced multiphoton ionization (2+1 REMPI). Kinetic energies of desorbed molecules were obtained by measuring the flight time of D2+ ions in a field‐free region. The mean kinetic energies determined from these measurements depend strongly on the rotational and vibrational states. Analyzing these results using the principle of detailed balance confirms previous observations that vibrational energy is effective, though not as effective as tr...