Materials Literature
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When containerless electromagnetic levitation processing was applied to elemental semiconductor Si using a two-step heating method proposed by the present authors, a substantial degree of undercooling up to 420 K (0.25 T m , T m is the melting temperature, 1685 K for Si) has been reproducibly achieved in slowly cooled…
For the first time switchable ferroelectric Langmuir-Blodgett films are prepared and investigated. The films with a regular multilayered structure are prepared from the ferroelectric copolymer of vinylidene fluoride with trifluoroethylene P(VDF-TrFE). The films with the thickness of 150 Å show a phase transition of th…
Results of optical absorption, photoluminescence, fluorescence lifetime and fluorescence-line-narrowing studies on several -doped crystals with the gallogermanate crystal structure are presented. Such crystals are unusual in that most fluoresce via both the broad-band transition and the sharper transition (R line), bo…
The first ethylene-bridged bis(chlorins) (for example 1) were obtained by coupling reactions of formylchlorins, either as the nickel(II) or zinc(II) complexes, with lowvalent titanium. They can be partially oxidized at reflux in toluene/acetic acid to afford trans-chlorin/porphyrin compounds, or fully oxidized with is…
We study the diffusion and submonolayer spreading of chainlike molecules on surfaces. Using the fluctuating bond model, we extract the collective and tracer diffusion coefficients ${D}_{c}$ and ${D}_{t}$ with a variety of methods. We show that ${D}_{c}(\ensuremath{\theta})$ has unusual behavior as a function of the co…
Von der Natur abgeleitet ist das Prinzip der symmetriebestimmten Selbstorganisation, das auf nicht zueinander passenden Koordinationszahlen beruht und das hier genutzt wurde, um einen auf Metall‐Ligand‐Wechselwirkungen basierenden Cluster zu entwerfen. Der rechts gezeigte Zehnkomponentencluster demonstriert die vorher…
A negative allosteric effect is observed in the [2]pseudorotaxane incorporating the 1,5-dioxynaphthalene derivative stoppered at one end by the [18]crown-6 macrocycle when it binds alkali metal cations. This effect can be exploited to elicit an optical response that can be monitored by UV spectroscopy. The principle i…
Photon-excited B K fluorescence spectra were measured for hexagonal boron nitride using tunable synchrotron radiation below and above the B K edge. We report Raman-like resonant inelastic scattering of soft x rays involving excitation of delocalized valence-band electrons. The inelastic scattering features track with…
A single multiwalled carbon nanotube with an outside diameter of about 12 nm and an inside diameter of about 4 nm has been isolated in order to measure its electrical properties (resistivity, transverse magnetoresistance and temperature dependence of resistance). The semi-metallic character of the conductance of the s…
In situ x-ray diffraction studies were performed on the PLSnZT antiferroelectric–ferroelectric phase switching ceramic and polycrystalline powder. The crystallography of both the antiferroelectic and electric-field-induced ferroelectric phases were determined for the approximate composition of Pb0.98La0.02(Zr0.55Sn0.3…
Neutron diffraction measurements on the title compounds have been carried out over a range of temperature from 10 to 300 K. The compounds have a rhombohedrally distorted perovskite structure. A paramagnetic to ferromagnetic transition is observed for samples with . The ordered magnetic moments obtained for x = 0.2 and…
By using the cold plasma torch we developed, TiO2 films were deposited on substrates exposed to air by feeding Ti(OEt)4 into the plasma. XPS and x-ray analyses revealed that all films were stoichiometric and amorphous TiO2, but Raman spectra indicated the existence of short-range crystallinity in films deposited above…
Neutron scattering has been used to study the magnetic correlations and long wavelength spin dynamics of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ in the ferromagnetic regime $(0\ensuremath{\le}x<\frac{1}{2})$. For $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\frac{1}{3}$ $({T}_{…
Transfer of MPEG(1900)-DSPE from micellar phase to pre-formed liposomes imparts long in vivo circulation half-life to an otherwise rapidly cleared lipid composition. MPEG(1900)-DSPE transfers efficiently and quickly in a time and temperature dependent manner. There is negligible content leakage and a strong correlatio…
The drainage of liquid in a foam may be described in terms of a nonlinear partial differential equation for the foam density as a function of time and vertical position. We review the history and recent development of this theory, analysing various exact and approximate solutions and relating them to each other.
The nonlinear optical crystal KBe2BO3F2 has been used to produce vacuum ultraviolet second-harmonic generation with an output range of 200–184.7 nm. The Sellmeier equation further indicates that this new crystal can generate the sixth harmonic from Nd-based laser systems.
The antiferromagnetic to ferromagnetic transition in L${\mathrm{a}}_{0.5}$C${\mathrm{a}}_{0.5}$Mn${\mathrm{O}}_{3}$ is accompanied by a commensurate to incommensurate charge-ordering transition. The presence of incommensurate charge correlation in the ferromagnetic phase is a remarkable interplay between charge and sp…
The stability of Ne@C$_{60}$ and He@C$_{60}$ is discussed in the context of a spherical model where the carbon atoms are smeared out into a uniform shell. The electronic properties of the sixty $π$ electrons together with those of the central atom are treated in the Thomas-Fermi approximation. Simple electrostatic rea…
Bales of antioxidant-stabilized guayule rubber underwent significant losses in bulk viscosity when stored under ambient conditions at an Arizona processing facility. Previous work implicated the unsaturated fatty acid esters present in entrained resin as promoters of such degradation. Aging studies as functions of sto…
Dielectric and dilatometric investigations of (NH2(CH3)2)2CoCl4 crystals were performed in the temperature range 290 to 430 K. Anomalies characteristic of phase transitions have been found at the temperatures 419, 380, 353, and 313 K (in a heating run). In certain phases the investigated crystal shows anomalously high…