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。
Ab initio electronic structure calculations based on gradient corrected density-functional theory were performed on a class of novel quaternary compounds AgPb(m)SbTe(2+m), which were found to be excellent high temperature thermoelctrics with a large figure of merit ZT approximately 2.2 at 800 K. We find that resonant…
We experimentally and theoretically studied a new left-handed (LH) structure based on a photonic crystal (PC) with a negative refractive index. The structure consists of triangular array of rectangular dielectric bars with dielectric constant 9.61. Experimental and theoretical results demonstrate the negative refracti…
We review basic computational techniques for simulations of various magnetic properties of solids. Several applications to compute magnetic anisotropy energy, spin wave spectra, magnetic susceptibilities and temperature dependent magnetisations for a number of real systems are presented for illustrative purposes.
A computer program LMTART for electronic structure calculations using full potential linear muffin-tin orbital method is described
We present optical measurements of random arrays of aligned carbon nanotubes, and show that the response is consistent with conventional radio antenna theory. We first demonstrate the polarization effect, the suppression of the reflected signal when the electric field of the incoming radiation is polarized perpendicul…
BiFeO 3 was studied as an alternative environmentally clean ferro/piezoelectric material. 200-nm-thick BiFeO3 films were grown on Si substrates with SrTiO3 as a template layer and SrRuO3 as bottom electrode. X-ray and transmission electron microscopy studies confirmed the epitaxial growth of the films. The spontaneous…
Abstract Failures, due to stress corrosion cracking (SCC), of corrosion resistant alloy (CRA) production tubing or sand control screens have been reported in recent years. Increased use of CRA materials for downhole applications is the result of stringent requirements for high-temperature high-pressure and sweet/sour…
Single crystals of K 2 Mg 2 (SCN) 6 ·3H 2 O were obtained by the reaction of the binary compounds MgCl 2 · x H 2 O and KSCN at 220° using the Bridgman technique. The compound crystallizes hexagonally with the noncentrosymmetric space group P 6 3 cm ( Z = 2, a = 885.2(1) pm, c = 1732.7(3) pm, R1 all = 0.1035). In the c…
Abstract Ordered three-dimensional (3-D) cage-like mesoporous mixed tungsten–titanium oxides (WO3–TiO2) with relatively high surface area (152 m2g−1) have been synthesized by employing Pluronic F108 triblock copolymer as a structure-directing agent via “acid-base pairs” strategy. Such materials exhibit enhanced electr…
Muons as a probe of magnetism in molecule-based low dimensional magnets, Tom Lancaster, Stephen J Blundell, Francis L Pratt, Michael L Brooks, Jamie L Manson, Euan K Brechin, Cyril Cadiou, David Low, Eric J L McInnes, Richard E P Winpenny
Previously it was shown by experiments that nanophase separation of incompatible main- and side-chain parts occurs in higher poly( n -alkyl acrylates) (P n AA) and poly( n -alkyl methacrylates) (P n AMA). Alkyl groups of different monomeric units of the polymer aggregate in the melt and form self-assembled alkyl nanod…
The syntheses and metal-responsive properties of poly(p-phenyleenethynylene)s with grafted new pseudo-crown-ether groups are reported. These polymers exhibit high sensitivities to alkali ions because of their collective optical properties, which are very sensitive to ion-induced conformational changes. The quenching o…
A molecular dyad has been synthesized in which free-base porphyrin and ruthenium(II) bis(2,2‘:6‘,2‘ ‘-terpyridine) subunits are linked via a meso -phenylene group. The distal terpyridine ligand bears a single phenylethynylene group. Selective illumination into the metal complex is followed by rapid intramolecular trip…
The structure of metal nanoparticles templated by amphiphilic hyperbranched polyethylenimine-amides in apolar organic solution was studied by means of small-angle neutron scattering (SANS). SANS measurements at different concentrations revealed that the neat polymer is present as nonaggregated unimolecular micelles fo…
Abstract Diarylmaleimide derivatives having methoxy, phenyl, or cyano group as a nitrogen substituent were synthesized in an attempt to prepare photochromic compounds which exhibit photochromic reactivity even in polar solvents. Although the derivatives having methoxy or phenyl group did not undergo photochromism in p…
Modified polyguanidines were prepared, and their liquid crystalline properties were studied using optical polarizing microscopy and X-ray diffraction. Parameters examined include chirality, the uniformity of the lengths of side chains, and attached side-chain mesogens. If the side chains on the repeat units are identi…
In this paper, we study three symmetrical D-pi-D chromophores containing dithieno[3,2-b:2',3'-d]thiophene (DTT) as the pi-center and various donor end moieties, by means of UV-vis-NIR and FT-Raman spectroscopy and in situ spectroelectrochemistry. The compounds display dual redox properties: all exhibited two oxidation…
Scanning tunneling microscopy (STM), in conjunction with the nucleation and growth of Au clusters, has been used to identify and quantify various types of defects on ordered, SiO 2 thin films grown on Mo(112). On a low-defect surface, Au clusters nucleate and grow at line defects with metal deposition at room temperat…
Arrayed, needlelike nanostructures of rutile phase crystal TiO 2 were grown on a Si substrate containing TiO 2 seeds prepared through a thin polystyrene- b -poly(4-vinylpyridine) (PS- b -P4VP) diblock copolymer template. The morphology of the deposited TiO 2 nanostructures was characterized by field-emission scanning…
Linear flexible polymers of N g monomers, end-grafted at the density σ onto a spherical surface of radius R (“hairy sphere”), including the case of a flat impenetrable wall ( R → ∞), are simulated using the cooperative motion algorithm. The simulations have been carried out for a wide range of parameters characterizin…