Materials Literature
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Scanning tunneling spectroscopy is used to investigate single InAs nanocrystals, 20--70 \AA{} in diameter, in a highly asymmetric double barrier tunnel junction configuration. The $I\ensuremath{-}V$ characteristics reflect contributions of both single-electron charging and the atomiclike level structure of the quantum…
Moir\'e contrast between monolayer graphite and Pt(111) lattices is observed in local tunneling barrier height (LBH) images, where LBH's are calibrated with quasistatic $I\ensuremath{-}z$ measurements. The observed Moir\'e amplitude of 1.6 eV, much larger than the possible maximum amplitude due to the electronic inter…
The presence and concentration of nitrogen and hydrogen impurities in thick diamond films grown by microwave plasma chemical vapor deposition at various H2 gas flow rates, keeping a constant [CH4]:[H2]=2.5% concentration ratio, have been determined by electron spin resonance and optical absorption spectroscopy. The re…
In this article we report on the atomic displacement parameters, lattice expansions, heat capacity, and thermal conductivity of samples of Ti4AlN3 in the 298–1370 K temperature range. Rietveld refinement of high temperature neutron diffraction data shows that the nitrogen is substoichiometric and the formula is Ti4AlN…
Ceramics with composition Ba 1- x Na x Ti 1- x Nb x O 3 are of either classical ferroelectric (for 0 ⩽ x < 0.075) and ferro- or antiferroelectric (for 0.55 < x ⩽ 1) or relaxor ferroelectric type (for 0.075 ⩽ x ⩽ 0.55), the transition at T c being only diffuse without any frequency dispersion for this last region. All…
Sterically stabilized biocompatible poly(lactic acid) (PLA) nanospheres were prepared by an o/w emulsion/evaporation technique, using hydrophobically modified dextrans (DexP) as the emulsion stabilizer. Photon correlation spectroscopy, zetametry, and differential scanning calorimetry studies corroborated that interfac…
Photoluminescence (PL) from ${\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{Ge}}_{x}$ alloy nanocrystals $(\mathrm{nc}\ensuremath{-}{\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{Ge}}_{x})$ as small as 4--5 nm in diameter was studied as a function of the Ge content. The $\mathrm{nc}\ensuremath{-}{\mathrm{Si}}_{1\ensuremath{-}x}{\…
Comprehensive neutron-powder diffraction and Rietveld analyses were carried out to clarify the relation between the crystal and magnetic structures of La2-2xSr1+2xMn2O7 (0.30 =< x =< 0.50). The Jahn-Teller (JT) distortion of Mn-O6 octahedra, i.e., the ratio of the averaged apical Mn-O bond length to the equatorial Mn-…
Raman backscattering measurements were performed on boron and phosphorous doped polycrystalline silicon films with an average grain size varying between 150 and 2500 nm. The B- and P-doped samples exhibit free hole and electron concentrations of up to $5\ifmmode\times\else\texttimes\fi{}{10}^{20}$ and $2\ifmmode\times…
We study the 38-atom Lennard-Jones cluster with parallel tempering Monte Carlo methods in the microcanonical and molecular dynamics ensembles. A new Monte Carlo algorithm is presented that samples rigorously the molecular dynamics ensemble for a system at constant total energy, linear and angular momenta. By combining…
We examine the relative stability of both stoichiometric and nonstoichiometric ${\mathrm{N}\mathrm{b}/\mathrm{A}\mathrm{l}}_{2}{\mathrm{O}}_{3}$ interfaces and ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ surfaces. Results of first-principles computations of surface and interfacial atomic relaxations, electron-density distribu…
The relationship between nanostructure and properties in polysiloxane layered silicate nanocomposites is presented. Solvent uptake (swelling) in dispersed nanocomposites was dramatically decreased as compared to conventional composites, though intercalated nanocomposites and immiscible hybrids exhibited more conventio…
High-resolution angle-resolved photoemission spectroscopy (ARPES) was used to investigate the transition metal dichalcogenide (TMC) $1T\ensuremath{-}{\mathrm{TiSe}}_{2}$ above and below the phase transition. We find that this system fulfills special conditions such as narrow band width and flat dispersion for bands wi…
In this paper, a model is proposed for the kernel in the generalized mixing rule recently formulated by Anderssen and Mead (1998). In order to derive such a model, it is necessary to take account of the rheological significance of the kernel in terms of the relaxation behaviour of the individual polymers involved. Thi…
This paper discusses a theory of natural circular dichroism in the x-ray region. Integrated spectra are interpreted in terms of microscopic effective operators, which are derived in the framework of a localised (atomic) model. It is shown that the generators of a de Sitter group, such as that introduced by Goshen and…
The simplest anharmonic characteristics of Ir and Rh are discussed in the framework of a previously developed simple pseudopotential model which describes the elastic moduli, phonon spectra and the lattice heat capacity in the harmonic approximation of these metals succesfully. The microscopic Gruneisen parameters, th…
The heat capacity and isomer distributions of the 38-atom Lennard-Jones cluster have been calculated in the canonical ensemble using parallel tempering Monte Carlo methods. A distinct region of temperature is identified that corresponds to equilibrium between the global minimum structure and the icosahedral basin of s…
An effective-mass Hamiltonian is derived for carbon nanotubes in the presence of a weak spin-orbit interaction. The spin-orbit interaction gives rise to terms corresponding to a kind of a spin-Zeeman energy due to magnetic fields in the circumference and axis direction. As a result spin scattering is induced even by s…
A new process was developed to fabricate electrically conducting nylon 6/graphite nanocomposites via intercalation polymerization of ϵ-caprolactam in the presence of expanded graphite. The transition from an electrical insulator to an electrical semiconductor for nylon 6 occurred when the graphite volume content was 0…
New tissue engineering technologies will rely on biomaterials that physically support tissue growth and stimulate specific cell functions. The goal of this study was to create a biomaterial that combines inherent biological properties which can specifically trigger desired cellular responses (e.g., angiogenesis) with…