Materials Literature
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Fine tip structures are required for many applications in different technologies, for example in scanning probe microscopy or vacuum microelectronic devices. Tips can be produced with nanometre precision by the electron-beam-induced deposition technique. The deposition process, however, is still not really understood.…
40π‐Elektronen und zehn Pyrrol‐Einheiten enthält der Makrocyclus 1 , das bisher größte expandierte Porphyrin. Das Tetrahydrochlorid von 1 wurde in Lösung und im Festkörper charakterisiert; nach diesen Untersuchungen liegt der Makrocyclus als Enantiomerenpaar vor, was auf einer Verdrillung des Ringsystems beruht. magni…
ZnO and ZnO:Li films (1-3 mu m thickness) were deposited on a soda lime glass substrate by a spray pyrolysis technique using ZnCl 2 and LiCl as starting materials. Physical properties of these films were studied as a function of substrate temperature T s and lithium concentration. The best ZnO film was obtained for T…
Some empirically founded expressions are established that aim to describe the backscattering coefficient and the energy distributions of electrons backscattered from a bulk solid target (atomic number Z>or=4) within the incident energy region 0.5<or=E 0 <or=100 keV, and for any incidence angle 0<or= Theta <or=60 degre…
1.3 μm to visible upconversion is observed in a BaCl2:Dy,Er phosphor system. Yellow fluorescence is visible under 1.3 μm laser diode (5 mW) irradiation. Radiative transitions from the 4S3/2 and 4F9/2 levels to the ground level 4I15/2 of the Er3+ ions cause fluorescence lines at 550 and 670 nm, respectively. This indic…
The dynamic conductivity has been measured in ${\mathrm{K}}_{0.3}$${\mathrm{MnO}}_{3}$ single crystals in the conducting phase (above 180 K), for the first time over a broad frequency range 1-${10}^{5}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, using a combination of different spectroscopic techniques. Together with…
It is demonstrated that a surface energy anisotropy (anchoring) defines the growth pattern of the field-induced transition in a smectic-$A$ liquid crystal (Sm-$A$). The stable domain phase nucleates as rounded domains but expands as stripes. The change in growth pattern is accounted for a large anchoring strength ${W}…
We show that ferromagnetic films separated by a spacer of amorphous Si are exchange coupled for Si thicknesses ${d}_{\mathrm{Si}}\ensuremath{\le}40$\AA{}. For $14\AA{}<{d}_{\mathrm{Si}}<22\AA{}$ we observe antiferromagnetic coupling. The coupling strength of approximately 5 \ifmmode\times\else\texttimes\fi{} ${1…
I present observations of interfacial tension between miscible pairs of silicate liquid and propose a theoretical model that quantitatively accounts for them. Viscoelastic rheology of the liquids permits the establishment of gradient stress completely analogous to thermal stress in Maxwell solids; this is expected whe…
The addition of 0.4–8.6 at. % Co to Cu thin films strongly influences the temperature evolution of microstructure, stress, and resistivity. For concentrations near 1 at. % Co in coevaporated Cu-Co on oxidized Si, normal grain growth begins at about 75 °C, about 50 °C lower than in pure Cu. There is an abrupt decrease…
We provide a theoretical explanation for the observed quasiuniversality of the ratio of the long-time to short-time self-diffusion coefficients in the colloidal liquids at freezing. We also predict that the mean-squared displacement at freezing, plotted against a suitably renormalized time, yields a universal curve sh…
Abstract Isotactic polypropylene was grafted with maleic anhydride using benzoyl peroxide as an initiator and toluene as a solvent. Effects of various parameters such as monomer and initiator concentration, reaction time, and reaction temperature on percentage grafting were studied. Effect of various solvents on exten…
Abstract The structure of oriented polyaniline (PANI) films were characterized by elemental analysis, FTIR, XPS, SEM, and X‐ray diffraction, and their electrical properties were measured as a function of the protonation state, elongation ratio, temperature, and applied pressure. A maximum conductivity at room temperat…
The blue and infrared (IR) bands of the photoluminescence spectra in the temperature range 11-430 K and excitation bands at 77 and 300 K of zinc tungstate single crystals have been studied. The line shape, obtained from the theory of lattice relaxation and multiphonon transitions, is compared with the experimental res…
Electrical conductivity (σ) and thermopower measurements have been carried out on some Mg 1+x Ge x Fe 2−2x O 4 (0 < x < 0.4) ferrite samples over a temperature range 300–700 K. Using the experimental values of Seebeck coefficient at various temperatures, the values of charge carrier concentration have been deter…
The relaxation time of the magnetization of a big magnetic molecule is evaluated. Isotropic exchange is assumed to be dominant, resulting in a fixed spin modulus s (equal to 20 in the case of interest). A perturbation of the form AS z 2 results from spin-orbit coupling and produces an energy barrier As 2 which separat…
\nThe growth of micron-size carbon fibres from thermal decomposition of hydrocarbons catalyzed by a metal has been widely studied. Coil-shaped fibres often grow among straight or twisted filaments. Their internal structure has not been studied in detail as yet. In the present work, the thermal cracking of acetylene on…
This book is a comprehensive design text for permanent magnets and their application. Permanent magnets are very important industrially, and are widely used in a variety of applications, including industrial drives, consumer products, computers and cars. In the early 1970s a new class of magnet - the rare earths - was…
Human tryptophan hydroxylase has been expressed as a soluble and active form in Escherichia coli by fusion with an affinity tag, maltose-binding protein. The fusion protein has been purified to near homogeneity by affinity chromatography on crosslinked amylose resin. The purified fusion protein has a specific activity…
Abstract Rubber toughening of thermoplastic polymers always decreases the tensile and flexural properties. In this article, an attempt is made to improve the tensile and flexural properties of a rubber‐toughened polymer system viz., polypropylene (PP)/styrene‐ethylene‐butylene‐styrene tri‐block copolymer (SEBS) binary…