Materials Literature
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The interfacial interactions between in situ thermally evaporated Au and polycarbonate (PC) film, a technologically important polymeric material, is studied by x-ray photoelectron spectroscopy (XPS). Angle resolved XPS is performed to investigate the Au reactivity if any, in forming the metal-polymer interface. The sp…
A difference in thermal expansion between a thin film and its substrate causes mechanical stresses in the film. Therefore, knowledge of the thermal expansion coefficients of thin films are important for their technological applications. In this article, we present an analysis which can be used to extract the thermal e…
We have investigated the transport properties of two-dimensional arrays of normal islands interconnected by tunnel junctions fabricated close to a conducting ground plane. For bias voltages $V$ below a threshold voltage ${V}_{\mathrm{th}},$ the current $I$ is thermally activated with an activation energy proportional…
The excellent magnetic properties of nanoscaled composite magnets can only be obtained by imposing strong requirements on the grain structure. The soft magnetic phase with a maximum extension smaller than 20 nm should be embedded into a hard magnetic environment. Furthermore the grain boundaries should be as ideal as…
Distributions of neutral Si-clusters centered around mean sizes of 50 and 200 atoms have been produced using a laser vaporization source and deposited on various substrates at room temperature in ultrahigh vacuum. The Si-cluster assembled films obtained, resulting from the random stacking of incident free nanosize clu…
Pressure influence on the electronic band structure of NiAs-type CrTe is studied for non-magnetic, ferromagnetic and antiferromagnetic states by using a self-consistent LAPW method. The total energy is calculated as a function of the lattice spacing a , keeping the ratio c / a as the observed value. The ferromagnetic…
A computer simulation of molecular dynamics is carried out to study the effects of a sigma 5 twist boundary on the formation of displacement damage cascades in silver. When a displacement damage cascade forms near the boundary, interstitial atoms are attracted and segregate on the boundary. The number of Frenkel defec…
We study the elastic properties of homopolymer/homopolymer interfaces containing diblock copolymers by means of a theory of Gaussian fluctuations. The interfacial tension and the bending rigidity of the interface in the two-phase coexistence region are calculated from the power spectrum of capillary modes. Our theory…
The dynamics of comblike polymers with a methacrylic backbone and flexible side chains were investigated by frequency and temperature dependent dielectric measurements. The cooperative motions of the main-chain segments and the side chains were first characterized in an amorphous polymer, i.e., the homopolymer of oleo…
X-ray photoemission spectroscopy (XPS) measurements have been performed on the intermetallic compounds ${\mathrm{Ni}}_{2}\mathrm{ZrSn},$ ${\mathrm{Ni}}_{x}{\mathrm{Zr}}_{1\ensuremath{-}x}\mathrm{Sn},$ ${\mathrm{Co}}_{2}\mathrm{ZrSn},$ and ${\mathrm{Co}}_{x}{\mathrm{Zr}}_{1\ensuremath{-}x}\mathrm{Sn}.$ The XPS valence…
At low fluences, the [Sr]/[Ti] ratio of laser deposited SrTiO3 films appears to be a function of the laser fluence. The deviation from stoichiometry is remarkably constant in time. From an analysis of both the composition of the film and the irradiated target, we deduce a volume-diffusion-assisted preferential ablatio…
This paper reports the calculation of electronic structure and linear optical properties of ${\mathrm{LiB}}_{3}{\mathrm{O}}_{5}$ (LBO), ${\mathrm{CsB}}_{3}{\mathrm{O}}_{5}$ (CBO), and ${\mathrm{BaB}}_{2}{\mathrm{O}}_{4}$ (BBO) crystals using the linearized augmented plane-wave band method. It is found that the top of…
We have evaluated the surface free energies of hydrogen-covered (100), (111), and (110) surfaces of diamond and silicon as a function of the hydrogen chemical potential using first-principles methods. The change in surface-energy anisotropy and equilibrium crystal shape due to hydrogen adsorption is examined. The thre…
We propose a very simple model of lattice dynamics of carbon nanotubes. Using a De Launay model, the atomic force constants and phonon density of states are given as functions of the nanotube radius. Elastic constants, a Young modulus, and Poisson ratio are derived from phonon dispersion curves for a homogeneous defor…
Formation kinetics of oxygen–hydrogen (O–H) complexes which give rise to an infrared absorption line at 1075.1 cm−1 have been studied in Czochralski-grown silicon crystals in the temperature range of 30–150 °C. Hydrogen was incorporated into the crystals by high temperature (1200 °C) in diffusion from H2 gas. It was f…
The oxidation of dissolved inorganic azide anion in aqueous media was investigated using high-quality, boron-doped diamond thin-film electrodes. Linear sweep and differential pulse voltammetry, along with flow injection analysis in the amperometric detection mode, were used to study the reaction at neutral pH as a fun…
The in-plane $({\ensuremath{\rho}}_{a})$ and $c$-axis $({\ensuremath{\rho}}_{c})$ resistivities of natural single-crystal graphite have been measured from 4 to 450 K at zero pressure and from 77 to 450 K under pressures up to 500 MPa. Data for ${\ensuremath{\rho}}_{c}$ differ strongly from earlier results obtained on…
Co–Pd alloy melts are characterized by a low heat of fusion and, as a consequence, by a comparably small critical undercooling for the hypercooling limit ΔThyp of the order of 300 K. It is shown that containerless processing of bulk melts by electromagnetic levitation offers undercooling levels of ΔT≈350 K thus exceed…
The effects of temperature on the kinetic parameters kcat and Km, for three isolates of the highly conserved monomeric enzyme 3-phosphoglycerate kinase (PGK), were investigated in detail using a rapid automated kinetics apparatus. PGK was purified from the thermophilic bacterium Thermoanaerobacter sp. Rt8.G4 (optimum…
In this study, we cloned and sequenced a DNA fragment from an ordered cosmid library of Helicobacter pylori NCTC 11638 which confers to a siderophore synthesis mutant of Escherichia coli (EB53 aroB hemA) the ability to grow on iron-restrictive media and to reduce ferric iron. Sequence analysis of the DNA fragment reve…