Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Magnetic properties of high-quality Al-free nonsuperconducting GdBa_2Cu_3O_{6+y} single crystals grown by flux method have been studied. The magnetic anisotropy below the Néel temperature T_N~2.3K corresponds to the direction of Gd^{3+} magnetic moments along the tetragonal c-axis. At T < T_N clear indications of spin…
Quasicrystals can carry, in addition to the classical phonon displacement field, a phason displacement field, which requires a generalized theory of elasticity. In this paper, the third-order strain invariants (including phason strain) of icosahedral quasicrystals are determined. They are connected with 20 independent…
In this study, we examine the dynamics of a one-dimensional Frenkel-Kontorova chain consisting of nanosize clusters (the ''particles'') and photochromic molecules (the ''bonds''), and being subjected to a periodic substrate potential. Whether the whole chain should be running or be locked depends on both the frequency…
A first-principles disordered local moment (DLM) picture within the local-spin-density and coherent potential approximations (LSDA+CPA) of the actinides is presented. The parameter free theory gives an accurate description of bond lengths and bulk modulus. The case of $δ$-Pu is studied in particular and the calculated…
Polycrystalline samples of LiBC compounds, which were predicted as possible candidate for high-Tc superconductivity, have been synthesised by a flux method and investigated by means of electrical resistivity and magnetic susceptibility. Scanning electron microscopy and X-ray diffraction patterns showed a plate-like mo…
We report experimental evidence of the existence of two variants of the ${E}_{\ensuremath{\gamma}}^{\ensuremath{'}}$ centers induced in silica by \ensuremath{\gamma} rays at room temperature. The two variants are distinguishable by the fine features of their line shapes in paramagnetic resonance spectra. These feature…
We give a brief review of some generalized continuum theories applied to the crystals with complicated microscopic structure. Three different ways of generalization of the classical elasticity theory are discussed. One is the high-gradient theory, another is the micropolar type theory and the third one is the many-fie…
To characterize porous media, use is often made of the Lucas−Washburn equation, which relates the rate of capillary penetration of a given liquid to an effective cylindrical pore radius and the contact angle between the liquid and the medium. Here, we extend previous large-scale molecular dynamics simulations develope…
This letter describes the preparation, characterization, material properties, and biodegradability of polylactide (PLA)-layered silicate nanocomposite. Montmorillonite modified with trimethyl octadecylammonium cation was used as an organically modified layered silicate (OMLS) for the nanocomposite preparation. WAXD an…
The structural, electronic, and magnetic properties of ${\mathrm{Co}}_{2}\mathrm{Mn}X$ $(X=\mathrm{Si},$ Ge, Sn) Heusler compounds have been determined by means of all-electron full-potential linearized augmented plane wave (FLAPW) calculations. We focus on the effects on the electronic and magnetic properties induced…
The structure of poly(l-lysine) (PLL)/hyaluronan (HA) polyelectrolyte multilayers formed by electrostatic self-assembly is studied by using confocal laser scanning microscopy, quartz crystal microbalance, and optical waveguide lightmode spectroscopy. These films exhibit an exponential growth regime where the thickness…
Birds in a cage: The highly absorbent nitrogen-rich compounds SrN and SrN2 hide their secrets from Raman scattering experiments, but when observed using inelastic neutron scattering, the dinitrogen can be shown to lie trapped within a cage of strontium atoms. Such a structure is shown in the graphic for SrN2, in which…
The alpha relaxation process of the fragile glass former salol is investigated in the T-P domain by means of photon correlation spectroscopy. We find that a time-pressure superposition principle is obeyed for the relaxation function in addition to the time-temperature superposition. The behavior of the relaxation time…
Dendrite morphology and evolution during coarsening is examined by the authors using measurements of the three-dimensional microstructure. Such experiments are made possible by recent progress in serial-sectioning techniques. The dendrite-matrix interface is characterized by the local interfacial curvature, which in t…
Abstract Physical aging experiments after a deep quench were performed via an optical photobleaching technique to examine the evolution of the segmental dynamics of a polystyrene melt far below the glass transition temperature ( T g ). Both rotational and translational diffusion measurements of dilute tetracene probes…
Thermodynamisch stabil, aber kinetisch labil sind die M3L2-Käfigverbindungen im hier gezeigten [BF4⊂{Ag3(MsTBim)2}](BF4)2 1 und [{CuI3⊂[Cu3(MsTBim)2]}2][Cu2I4] 2, wobei 2 ein bisher noch nicht beschriebenes Metallkomplex-Wirt/Metallkomplex-Gast-Arrangement aufweist. Größere Anionen wie CF3SO3− oder BPh4− lagern sich a…
The question of localization in a one-dimensional tight-binding model with aperiodicity given by substitutions is discussed. Since the localization properties of the well-known Rudin-Shapiro chain is still far from well understood, partly due to the absence of rigorous analytical results, we introduce a sequence that…
We have investigated the photoinduced optical properties of a new class of chiral methacrylic polymers characterised by the presence in the side chain of an optically active pyrrolidinyl ring linked to a trans-azoaromatic system. The homopolymers are enantiomerically pure and their strong optical activity indicates th…
Highly soluble [(tBu(4)PcM)(2)O] phthalocyanine dimers (M=Ga(III) (3), In(III) (4)) were prepared by the reaction of [tBu(4)PcMCl] (M=Ga(III) (1), In(III) (2)) with excess of concentrated H(2)SO(4) at -20 degrees C. The Mbond;Obond;M linkages in 3 and 4 are not stable against concentrated H(2)SO(4) at room temperature…
An effective method for incorporating cadmium ions into mesoporous silica SBA-15 is demonstrated. One of the novel features is the assembly of CdS nanoparticles inside the mesopores by selectively functionalizing the external surface of SBA-15 in order to avoid the possible adsorption of the cadmium ions onto this sur…