Materials Literature
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Ordered hexagonal mesoporous silica material (JLU-30) has been successfully synthesized in alkaline media at high temperature (>160 °C), using cationic (1,3-dimethyl-2-imidazolidin-2-ylidene)hexadecylmethylammonium bromide (DIHAB) as a template, and characterized with X-ray diffraction (XRD), transmission electron mic…
Two fundamental manifestations of Al conduction electron response to Ar atom core hole in the final state of photoemission have been studied in implanted Ar bubbles in Al(111). Ar 2p binding energy and the Doniach-Sunjić asymmetry of the core-level line shape vary systematically as functions of Ar+ implantation energy…
Mixed ammonium molybdenum/tungsten bronzes are available in nanoscopic form via a straightforward solvothermal synthesis in acidic media. The emerging rods exhibit average lengths below 1 μm and diameters of 20−30 nm. They self-organize into manifold microscale patterns. The growth of mixed nanorods proceeds within a…
Structural, mechanical and elastic behaviour, density of states, electronic charge density and band structure of V B 2 and ZrB 2 are studied by the ab initio density functional method. The calculations carried out using the gradient-corrected approximation of the density functional theory are in excellent agreement wi…
New optically pumped lasing cholesteric polymers able to respond to pH changes in the chemical environment are synthesized and studied. The polymer may be prepared as a free-standing film, with lasing turned on and off in basic and acidic aqueous solutions.
The first-order magnetostructural phase transition in ${\mathrm{Gd}}_{5}({\mathrm{Si}}_{x}{\mathrm{Ge}}_{1\ensuremath{-}x}{)}_{4}$ alloys with $x<~0.5$ and the related entropy change $\ensuremath{\Delta}S$ are analyzed from high-field magnetization curves up to 23 T, and differential scanning calorimetry up to 5 T.…
We present a resonant x-ray scattering study at the manganese K edge on ${\mathrm{La}}_{7/8}{\mathrm{Sr}}_{1/8}{\mathrm{MnO}}_{3}$ at temperatures between 10 K and 310 K along with thermal expansion, magnetization, and electrical resistivity measurements. At the Mn K edge the symmetry-forbidden (300) reflection is obs…
Long fibers of high purity single-walled carbon nanotubes (SWNTs) were directly synthesized macroscopically by the modified arc discharge method. The purity of SWNT in fibers that can be obtained, as high as 80% (volume), was evaluated by scanning electron microscopy, thermogravimetric analysis, and Raman spectroscopy…
Two two-dimensional azido-bridged Mn(II) coordination polymers with bidentate coligands have been synthesized and structurally characterized, and their magnetic properties were studied. The complexes are of formula [Mn(bphz)(N 3 ) 2 ] n ( 1 ) and [Mn(mipc)(N 3 ) 2 ] n ( 2 ), where bphz = 2-benzoylpyridine hydrazone an…
The theory of “pore blocking” is often used, particularly in combination with percolation theory, to develop methods of analysis for gas sorption data for the structural characterization of porous media. However, the evidence for the existence of the pore-blocking effect is conflicting and equivocal. In the work descr…
An integrated polarized light guide was designed and fabricated for use as a liquid-crystal backlight with emphasis on uniformity of the light and conversion of p-polarized to s-polarized light. Two different micro-optical structures were fabricated both on the top and the bottom surfaces of the light guide. On the to…
The Layer-by-layer deposition of positively and negatively charged macromolecular species is an ideal method for constructing thin films incorporating biological molecules. We investigate the adsorption of fibronectin onto polyelectrolyte multilayer (PEM) films using optical waveguide lightmode spectroscopy (OWLS) and…
High-quality mesoporous ethylenesilicas were prepared for the first time under acidic conditions using alkylpoly(ethylene oxide) oligomers or polyalkylene oxide triblock copolymers as supramolecular templates. Depending on the synthesis conditions, materials with medium (4−5 nm) and large (8−9 nm) mesopores were obtai…
Conformational properties of neutral and charged dendrimers in dilute solutions of different quality have been investigated by a mean-field analytical approach and by Brownian dynamics (BD) computer simulation for systems up to generation six. Radial monomer distribution and mass distribution functions, radii of gyrat…
We have investigated how an iron catalyst changes during the growth of vertically aligned carbon nanotubes by in situ measurement of X-ray diffraction. It is found that heating the catalyst film to a growth temperature of 700°C in He atmosphere induces its oxidation beyond 100°C due to adsorbed moisture and changes th…
We report results of electron paramagnetic resonance, magnetization, and optical absorption studies of bulk GaN crystals doped with Mn and, for some samples, codoped with Mg acceptor. The experiments performed show that the charge state of the Mn ion in GaN depends on the Fermi level position in the crystal. In $n$-ty…
In this paper, we report a novel route to the synthesis of high-quality, large-pore periodic mesoporous organosilicas (PMOs) using triblock copolymer P123 as a template. The novelty lies in that highly ordered PMOs can only be synthesized at a limited range of low acid concentrations, which differs from traditional ap…
Urea and urethane cross-linked hybrids, classed as di-ureasils and di-urethanesils, were prepared through sol−gel derived carboxylic acid solvolysis. The resulting nanohybrids were characterized by X-ray diffraction, mid-infrared spectroscopy, 29 Si and 13 C nuclear magnetic resonance, and photoluminescence spectrosco…
A new and simple method for preparing large-area and continuous calcium carbonate films under mild conditions is described. Amorphous calcium carbonate (ACC) films have been formed both in the presence and absence of a poly(acrylic acid) inhibitor. The transformation from ACC to crystalline vaterite/calcite has been o…
The magnetic pyrochlore oxide materials of general chemical formula R2Ti2O7 and R2Sn2O7 (R = rare earth) display a host of interesting physical behaviours depending on the flavour of rare earth ion. These properties depend on the value of the total magnetic moment, the crystal field interactions at each rare earth sit…