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Recent experiments have demonstrated that plastic strains in nanocrystalline aluminum and gold films with grain sizes on the order of 50 nm are partially recoverable. To reveal the mechanisms behind such strain recovery, we perform large scale molecular dynamics simulations of plastic deformation in nanocrystalline aluminum with mean grain sizes of 10, 20, and 30 nm. Our results indicate that the inhomogeneous deformation in a polycrystalline environment results in significant residual stresses in the nanocrystals. Upon unloading, these internal residual stresses cause strain recovery via competitive deformation mechanisms including dislocation reverse motion/annihilation and grain-boundary sliding/diffusion. By tracking the evolution of each individual deformation mechanism during strain recovery, we quantify the fractional contributions by grain-boundary and dislocation deformation mechanisms to the overall recovered strain. Our analysis shows that, even under strain rates as high as those in molecular dynamics simulations, grain-boundary-mediated processes play important roles in the deformation of nanocrystalline aluminum. grain-boundary diffusion | grain-boundary sliding | molecular dynamics simulation

Several experimental and computational studies are conducted to determine the forward current density ([J.sub.F])-forward voltage ([V.sub.F]) characteristics of 4H-silicon junction barrier Schottky (JBS) diodes. These characteristics are shown to be highly affected by the lateral spreading of the implanted aluminum ions and implantation-induced defects.

Aluminum ion doping to the Ni fully silicided/HfSiON gate stack is used to demonstrate a simplified method of effective work function control for n-channel metal-oxide-semiconductor. The formation of interfacial [Al.sub.2] [O.sub.3] layer at the Ni-FUSI/Si[O.sub.2] interface gives rise to opposite effective work function that has little influence on the effective work function value on the Ni fully silicided/HfSiON interface.

X-ray photoelectron spectroscopy (XPS) is employed to study the polyamide samples, which are modified by aluminum (Al) ions by filtered cathodic vacuum arc (FCVA), using with plasma immersion ion implantation (PIII) technique. The study reveals the chemical bond between implanted and deposited Al ions and the polyimide matrix, which is found to be extremely useful for the entire process.

Spatially resolved laser-induced breakdown spectroscopy (SRLIBS) was used for the characterization of aluminum and silicon in nickel-based alloys. The very low invasiveness of the technique was one of the figures of merit of LIBS; however, the relative complexity of the instrument often hindered the widely acceptance of LIBS. Spatially resolved LIBS could provide accuracy and precision comparable to those obtained with temporally resolved LIBS (TRLIBS). In the nongated spatially resolved LIBS, the maximum atomic emission could be obtained with relative low continuum background emission at optimum observation spatial position. The study was done with a Nd:YAG laser at 532 nm, 3.0 mJ laser energy, and 0.2 mbar in argon. The experimental results obtained under optimum conditions were compared to those obtained with TRLIBS. SRLIBS gave reliable results without the tedious optimization of the delay time and gate width.

Good linear correlations between GIAO-MP2 calculated (super 11)B NMR chemical shifts of boronium-onium cations and (super 13)C NMR chemical shift of the corresponding isoelectronic carbonium-onium dications as well as between (super 27)Al NMR chemical shifts of the alonium-onium cations and the (super 29) Si NMR chemical shifts of the corresponding isoelectronic siliconium-onium dications are observed.

The low energy backscattering co-efficient for the special case of film of carbon deposited on aluminum is investigated. The findings show for aluminum substrates, the position of the relative minima of the backscattering coefficient is increasing as the carbon film thickness increases.

A method is presented to achieve thick high quality crack-free AlGaN layers on GaN. This method uses jointly plastic relaxation and lateral growth. In order to explain the mechanism involved in the full relaxation of the AlGaN/GaN heterostructure, a relaxation scheme is proposed and discussed.

The results of a theoretical study of MnNn (M =Al, Ga, and In; n = 4,5,6) neutral and anionic clusters are reported that focus on the changes in structural and electronic properties upon the addition of an electron to the corresponding neutral clusters. The atomic charge analysis showed that the extra electron is localized on the metal atoms, irrespective of the lowest energy structural configurations of these clusters.

The nanoenergetic materials consisting of aluminum nanoparticle (50 - 200 nm) aggregates termed ALEX plus nitrocellulose (NC) oxidizer are studied by ultrafast spectroscopy following 100 ps laser flash-heating. The nanosecond-duration burst of light accompanying ignition triggered by vaporizing ALEX consists of a continuum peaked near 500 nm plus features associated with electronically excited Al atoms and hot excited AlO.

The photoelectron spectroscopy experiments on all-metal MAl4(super -) systems with approximate square planar Al4(super 2-) unit and an alkali metal led to the suggestion that Al4(super 2-) is aromatic. The results show that more than one independent delocalized bonding system could simultaneously satisfy the electron counting rule of aromacity, and therefore, a molecular structure could have multiple-fold aromacity.

A combination of W-band (super 1)H ENDOR and X-band HYSCORE spectroscopies has provided direct evidence of the coordination environment of Cu(super 2+) exchanged in zeolite Y. W-band (super 1)H ENDOR is used to probe the water ligands, whereas X-band hyperfine sublevel correlation (HYSCORE) spectroscopic measurements were employed to detect (super 27)Al hyperfine couplings.

The synthesis and characterization of bis(tetraethylammonium) dodecamethyl-closo-dodecaborate(2-), [NEt4](sub 2)[closo-B12Me12], [NEt4](sub 2) are reported. The X-ray crystallography reveals that the geometries of the B12 clusters observed are identical and essentially undistorted icosahedra.

The product energy and angular momentum distribution for dissociation of the Al(sub 6) and Al(sub 13) clusters are presented which are compared with the predictions of statistical theories. The report stated that EngelRing model for deducing the cluster dissociation energy from the measured does not give accurate results for Al(sub 6) and Al(sub 3) dissociations.

Nitrogen-incorporated SAPO-11 molecular sieves are synthesized by a secondary synthesis technique at low nitridation temperature (400 degree C) with a starting material of SAPO-11 zeolite doped with two wt % Ru. It was found that nitrogen-containing species had incorporated into framework of SAPO-11 zeolite, in which some N atoms directly bonded to Al and P atoms and formed AlN4, AlN2O2, and PN4 groups.

A new method is described for the formation of metal nanoparticles by sputter deposition inside the reaction ion etching chamber with a very short target-substrate distance. The distribution and morphology of nanoparticles are affected by the distance, the ion concentration and the sputtering time and a new mechanism is proposed based on the seeding effect of the substrate for interpreting the experimental results.

Dialkylalumenium cation equivalents coupled with the hexabromocarborane anion function as efficient and long-lived catalysts for alkylation of aliphatic C-F bonds (alkylative defluorination or AlkDF) by alkylaluminum compounds is described. The catalysis by alumenium is observed to offer more advantage over the uncatalyzed C-F activation in terms of both increased rate and, in some cases, significantly increased selectivity.

Threshold collision-induced dissociation techniques are utilized to determine the activation energies (AEs) and bond dissociation energies (BDEs) of metal cation-triethyl phosphate complexes, M(+)(TEP), where M(+) = Mg(+), Al(+), Cu(+), and Zn(+). The results provide insight into the loss of ethene, [C.sub.2][H.sub.4] due to activated dissociation which corresponded to the primary and lowest energy pathway for all four systems.

Density functional their calculations are used for studying the ligand-protected [Al.sub.7] and [Al.sub.77] clusters. The studies have shown that the shape, and thus the properties of Al nanoclusters are controlled by using ligands with different sizes.

The assembly of HS[(C[H.sub.2]).sub.15]X, with X = -C[H.sub.3] (M-SAM) and -C[O.sub.2]C[H.sub.3] (ME-SAM), on Au {111} substrates were used to carry out Al atom deposition with controlled coverages on self-assembled monolayers (SAMs) and microscopic and spectroscopic studies were conducted to analyze their structures and electrical properties. The experimental studies demonstrated a highly controlled, quantitative strategy to explore the chemistry of nascent metal atoms with organic moieties as well as provided route to generate novel metal nanostructures with significant implications for molecular and organic device applications.

The three-dimensional classical molecular dynamics simulation was used to examine the deposition and annealing behaviors of Al atoms on rough Cu (111) surface on the atomic scale. The significant intermixing between Al and Cu which rapidly occurs due to annealing at 700 K with decrease in the surface roughness provide insight into the exchange process of Al with substrate Cu during the initial stage of high temperature annealing.

The analysis has shown the efficient energy transfer from Si nanoparticles (NPs) to [Er.sup.3+] ions in a nonsilica-based material [Al.sub.2][O.sub.3]. The results have shown that a higher percentage of [Er.sup.3+] ions are sensitized by Si NPs and have stressed the importance of controlling the dopant distribution at the nanoscale to achieve improved device performance.

The gas electron diffraction (GED) method along with quantum chemical calculations were used to determine the molecular structures of chloro(phthalocyaninato)aluminum(III) (ClPcAl) and chloro(phthalocyaninato)-gallium(III) (ClPcGa). The results from calculations showed all the molecules to have [C.sub.4v] symmetry with the metal atom above the plane defined by the four inner cavity N atoms and an almost planar macrocycle.

The first study evidence for the hexatomic species, C[Al.sub.5.sup.+] cation which favors a [D.sub.5h] global-minimum planar pentacoordinate carbon (ppC) structure. The results from high-level ab initio computations and quantum molecular dynamics simulation revealed that the most stable C[Al.sub.5.sup.+] isomer exhibit [D.sub.5h] symmetry and is ~3.80 kcal/mol lower in energy than the second most stable alternative.

A series of alumino-carbon clusters, [C.sub.n][Al.sub.m](n=2-3, m=2-8) are computationally investigated at MP2 level of theory with correlation consistent basis sets augmented on carbon. Studied carbon-aluminum clusters exhibit a significant stability toward ionization and moderate electron attachment.

X-ray photoemission spectroscopy (XPS) was used to understand the mechanism and the interfacial interaction between the active organic layer and the cathode for polymer solar cells with cesium carbonate as an electron-injection interlayer. [Cs.sub.2]C[O.sub.3]/Al was found to form a better Ohmic contact with the organic layer and reduce the device series resistance.

Ti and Al K-edge x-ray absorption spectroscopy is used for examining the electronic structure of [Ti.sub.1-x][Al.sub.x]N thin films deposited by reactive magnetron sputtering. The x-ray absorption fine structure (EXAFS) has allowed structural information about both crystallized domains and grain boundaries, while x-ray diffraction has given the lattice symmetry and the sizes of the former.

Single-crystal low-temperature synchrotron X-ray diffraction is used for providing an accurate structural study for three members of the series [[Ca.sub.12][Al.sub.14][O.sub.32]][O.sub.1-[delta]][e.sub.2[delta]] ([delta] = 0, 0.15, and 0.45). The studies have indicated that the final electron density map for [delta] = 0.45 black mayenite has shown electron density localized into the center of the cages, which is the first experimental proof of their electride nature.

Density functional theory method is used to study the binding of cytosine to aluminum(Al), copper(Cu), and gold(Ag). In [(Al-cytosine).super. -1] the bonding shows electrostatic and covalent interactions and the negative atomic charge of Cu and Ag produce nonconventional hydrogen bonds in [(Cu-cytosine).super. -1] and [(Ag-cytosine).super.-1].

The characterization of thermodynamic properties of neural [Al.sub.n] (2 (less than or equal to) n (less than or equal to) 65) particles which provide insight into size-selective reactivity and catalytic activity of metal nanoparticles is reported.

Photoluminescence spectroscopy is used to study the luminescence mechanism of [Al.sub.x][Ga.sub.1-x]As/GaAs single quantum wells at low temperatures with differing aluminum concentrations in the barrier. The results verify that the observed standard deviation of the potential fluctuations increases with aluminum concentration in the barrier, in accordance to the AlGaAs alloy compositional disorder theory.

The thermodynamic properties of Al are calculated for two nonpairwise-additive potentials by using Monte Carlo simulations. The results have shown that the melting point for the embedded-atom model is higher than the experimental value and the embedded-atom (EAM) potential has yielded improved binding energies for smaller clusters, a small fraction of aggregates in the saturated vapor phase, and hence an accurate heat of vaporization and boiling point.

Mass spectroscopy, anion photoelectron spectroscopy, photoionization spectroscopy, and theoretical calculations were employed to investigate the geometric and electronic structures of aluminum binary clusters, [Al.sub.n]X (X = Si and P). Experimental and theoretical results reveal that Al12Si possesses a high ionization energy and low electron affinity and Al12P possesses a low ionization energy, both with the icosahedral structure having a central Si or P atom, revealing that Al12Si and Al12P exhibit rare-gas-like and alkali superatoms, respectively.

The reaction of LAIH2 with PhB([OH.sub.2]) is investigated to take advantage of the different polarity of the hydrogen atoms in both compounds, which should lead to easy hydrogen elimination. The investigation is conducted by locating a transition-state structure on the potential hypersurface and also by taking a closer look at the possible alternative mechanism.

The shearing of aluminum asperities by a 'hard' asperity is simulated by molecular dynamics. The relative importance of each factor and its interaction is analyzed by the design-of-experiment approach.

The protonation mechanisms of olefins in H-ZSM-5 at the DFT level of theory with representative cluster sizes to gain insights into the relative stability of alkoxy species are studied. The barriers and mechanism for their formation from olefins as well as the interaction of saturated paraffin molecules with Bronsted acid sites are also investigated.

Al and Ti into the framework of ordered mesoporpous silica materials in strong acidic media in the presence of triblock polymer template, resulting in the formation of mesoporous aluminosilicate (MAS-7) and mesoporous titanosilicate (MTS-9) is introduced. The results of the catalytic tests show that MAS-7 gives higher catalytic activity in the crackings of cumene and 1,3,5-triisopropylbenzene than Al-SBA-15, and MTS-9 provides higher catalytic activity in phenol hydroxylation by H2O2 than Ti-SBA-15.

A set of first principles calculations is conducted in order to determine the interaction of a (pi) bonded organic molecule with a simple s-p metal surface. The findings indicate that the binding between a (pi) and the (pi) orbitals of a simple metal atom cannot be extended to describe the binding with a p band of solid.

The novel intramolecular stabilized arylaluminum chalcogenides (ArAIE)(sub 2) (Ar = 2-(NEt(sub 2)CH2)-6-MeC6H3, 2,6-(NEt(sub 2)CH2)(sub 2)C6H3) were prepared by the reaction of the corresponding aluminum dihydrides with elemental selenium and tellurium. The results indicate that the dimeric form with one dangling NEt(sub 2) group is energetically favored in comparison to the corresponding monomeric species with two chelating arrangements at the aluminum atom.