Materials Literature
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The wetting properties of thin polystyrene (PS) homopolymer films (polymerization index ${N}_{H}$) were studied on the surfaces of polyvinylpyridine-polystyrene (PVP-PS) block copolymer films (polymerization indices ${N}_{\mathrm{PS}}$ and ${N}_{\mathrm{PVP}}$) oriented into lamellae with the PS block present at the v…
Abstract Superheating and double‐melting endotherms are the characteristic melting behaviors of gel‐spun ultra‐high modulus and molecular weight polyethylene (UHMWPE) fibers in differential thermal analysis (DTA). A mostly orthorhombic structure with very little amorphous content is indicated by wide angle x‐ray scatt…
We have investigated electrical transport in undoped diamond films prepared by chemical vapor deposition. Using an electrolytic decoration scheme we prove that currents flow predominantly on grain boundaries. From the temperature and the frequency dependencies we conclude that hopping transport takes place. The conduc…
The thermal conductivity of SiO2 and TiO2 optical coatings are measured in the temperature range 80–400 K. For SiO2, the thermal conductivity of sputtered and evaporated films are 77% and 55% of the bulk value, respectively, independent of temperature. Similarly, the thermal conductivity of evaporated TiO2 is 63% of t…
The effect of Fe substitutions by rare-earth ions on magnetic and electrical properties of a Ni-Zn ferrite prepared by the classical method is investigated. A set of seven compounds with formula Ni 0.7 Zn 0.3 Fe 1.98 R 0.02 O 4 , where R identical to Yb, Er, Dy, Tb, Gd, Sm or Ce, was prepared. Emphasis is placed on cu…
The dielectric constant ε, loss tan δ, and conductivity σ of aluminium doped zinc—manganese ferrites of general formula Zn0.3Mn0.7Fe2−xAlxO4 (with x values ranging from 0.2 to 1.0) are studied as a function of frequency, in the range 5 to 500 kHz and in the temperature range 30 to 150 °C. All these samples are found t…
Results are given of an investigation of the absorption processes at the absorption edge of the ternary system (GaxIn1−x)2Se3 in the In-rich region. In E ∥ c polarization, the absorption coefficient for all investigated concentrations exhibits an exponential dependence on photon energy following Urbach's rule. The ana…
Single crystals of gallium-gadolinium garnet (GGG) irradiated by fluences of fast neutrons (0 to 3.8 × 1024 m−2) are investigated by X-ray and magnetic methods. It is found that irradiation with high fluences leads to complete amorphization of the samples. Besides, the samples recover their single crystalline structur…
The phase behaviour of chloro-aluminium phthalocyanine, chloro-indium phthalocyanine, bromo-indium phthalocyanine, dichloro-tin phthalocyanine, and dichloro-platinum phthalocyanine is studied using differential scanning calorimetry, X-ray diffraction, and X-ray fluorescence. The shape of the thermograms obtained in th…
A comparative analysis for the results obtained by force and energetic approaches, which are used in calculations of equilibrium position of misfit dislocations near interfaces, is performed. It is shown that a correct utilization of both approaches leads to similar results for the models which do not consider the fin…
FelI(HPO3)8(OH)6 AND Mnll(HPO3)8(OH)6 phosphite groups on the threefold axis gave either unstable refinements or chemically unreasonable structures, hence all were left in the same orientation as in the Fe compound.MPA would like to acknowledge the University of California, Santa Barbara, for the provision of a schola…
The structure of α-dicalcium silicate hydrate, \nCa_2(SiO_3OH)(OH), has recently been described and \nrefined [Y ano, Urabe, Ikawa, Teraushi, Ishizawa & \nUdagawa (1993). Acta Cryst. C49, 1555-1559] in space group P2_12_12_1 (orthorhombic; a = 9.487 (4), b = 9.179 (4), c = 10.666 (7) Å, Z = 8). It is b…
Three-point bending and fracture toughness tests of alumina specimens with various grain sizes were carried out to investigate the effects of grain size on bending strength and fracture toughness. The bending strength increased with decreasing grain size. The intrinsic fracture toughness, which can be obtained by the…
Abstract The supramolecular structure formation in solutions of syndiotactic polystyrene is discussed from the viewpoint of the temperature-concentration behaviour of this system. The phase diagrams that result from these investigations localize the different temperature-concentration domains in which the β-phase (pla…
Raman scattering of ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As epitaxial layers on InP and GaAs substrates have been investigated with a wide range of composition. It is found that the asymmetric broadening of LO phonon modes varies with composition as well as substrate. With th…
Electrical transport is measured for a crystal and polycrystalline samples of ${\mathrm{Ni}}_{3}$${\mathrm{S}}_{2}$. The samples display metallic behavior with the relative resistance decreasing by more than two orders of magnitude upon cooling from 300 to 4.5 K. Low-temperature heat-capacity data are obtained by the…
The effect of thermal annealing on the conduction- and valence-band edges in porous silicon is studied by photoemission, Auger, and x-ray-absorption spectroscopies. The quantum shifts in the conduction- and valence-band edges of porous Si relative to bulk Si are found to decrease with progressively higher annealing te…
Diamondlike carbon (DLC) films were directly deposited onto germanium (Ge) and zinc sulphide (ZnS) slices by a capacitively coupled 13.56 MHz rf glow discharge plasma with Ar-C2H2 gas mixtures. The IR transmittance was measured using a Fourier-transform infrared spectrometer. The maximum values of the IR transmission…
Abstract Newton's method is applied to the finite volume approximation for the steady state heat transfer, fluid flow and unknown interfaces in a floating molten zone. The streamfunction/vorticity and temperature formulation of the Navier–Stokes and energy equations and their associated boundary conditions are written…
Electronic effects from two well-defined defects are identified and measured using scanning tunneling microscopy on graphite. An atomic vacancy on the topmost (0001) plane caused a lowering of apparent z height in a 30 \AA{}\ifmmode\times\else\texttimes\fi{}30 \AA{} area by \ensuremath{\sim}1.5 \AA{}. A plane rotation…