Materials Literature
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The authors demonstrate from their Raman and transmission electron microscopy results that the annealing ambient, temperature, and duration play a significant role in the formation, the evolution, and the crystallinity of Ge nanocrystals in silicon oxide matrix. With careful etching experiments, the authors establishe…
The authors report a cutting technique for carbon nanotubes (CNTs) assisted by the presence of oxygen gas. The cutting procedure is conducted in less than 1min using a low-energy electron beam inside a scanning electron microscope. The oxygen gas was regulated by a mass flow controller and was injected at 1SCCM. It wa…
We report molecular dynamics simulations for telechelic molecules composed of two polyhedral oligomeric silsesquioxane (POSS) cages connected by one hydrocarbon backbone dissolved in liquid normal hexane. Silsesquioxanes are novel hybrid organic-inorganic molecules that are useful as building blocks for the synthesis…
Abstract Calcium Carbonate has been precipitated from aqueous solutions containing different concentrations and different molecular weight of Polyethylene Glycol (PEG). The precipitations were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR) and X‐ray diffraction (XRD). T…
This feature article focuses on biodoped ceramics. These are inorganic materials in which biological materials are incorporated, thus adding new functionality to them. A brief overview of the prominent synthesis techniques for biodoped ceramics, with emphasis on modified sol–gel processes for metal oxide matrices, is…
The results on the synthesis, microstructure, structure and DC magnetization studies of nanocomposite Zn,Ni ferrite/NiO powder obtained by thermal decomposition of acetylacetonato complexes are reported in this paper. According to the results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OE…
The O program system and related programs are described. Topics covered include: RAVE, which is a suite of programs for electron-density map improvement and analysis; programs that interface with O for the analysis of protein models; utility programs; and internet-based services related to O and the associated program…
The authors report on ferromagnetism at room temperature in cluster-free, cobalt- and manganese-ion-implanted crystalline silicon. Through magnetic and structural analysis it is shown that the ion-implanted Si consists of two layers of Co- and Mn-containing silicon: (1) an amorphous Si layer on the surface and (2) sin…
The physical mechanism of He-ion-based exfoliation in Z-cut LiNbO3 is investigated. Rutherford backscattering/channeling, nuclear-reaction analysis, and transmission electron microscopy are used to examine the compositional and structural changes caused by deep ion implantation followed by thermal annealing. Lattice d…
Results from high-pressure synchrotron x-ray diffraction and high-temperature x-ray diffraction measurements on polycrystalline samples of the tetragonal perovskites Sr 2 GaSbO 6 , Sr 2 NiMoO 6 , and Sr 2 FeNbO 6 are reported. A phase transition, where the unit cell changes symmetry from tetragonal to cubic, is observ…
Highly oriented ZnO nanoneedle arrays were electrochemically prepared by anodization of zinc foil in a freshly prepared zincate saturated aqueous solution at room temperature. Typically, the needles have a length of 550–650 nm with a tip diameter of 10–15 nm and a root diameter of 50–60 nm, and grow along their [001]…
The authors study the electromagnetic surface waves localized at an interface separating a one-dimensional photonic crystal and left-handed metamaterial, the so-called surface Tamm states. They demonstrate that the metamaterial allows for a flexible control of the dispersion properties of surface states and can suppor…
An overview of the Rietveld method of analysing powder diffraction data, in which the crystal structure is refined by fitting the entire profile of the diffraction pattern to a calculated profile, is provided. The basic theory of Rietveld refinement is described and some problems that may lead to failure of the method…
The first section of this chapter concerns scattering factors for the diffraction of electrons by crystalline solids. An explanation of the theory of scattering by a perfect crystal is followed by a discussion of the kinematical, two-beam and phase-grating approximations. Relativistic and absorption effects are consid…
Despite the necessity of direct growth of single-walled carbon nanotubes (SWNTs) on conducting films for versatility of designing device architectures for nanoelectronics and optoelectronics, most of SWNT growths have been carried out on insulating films or supporting materials such as SiO2 and Al2O3. Here, the author…
Europium‐doped calcium sulfide phosphor was synthesized by a co‐precipitation method using calcium carbonate and ammonium sulfate as the sources for calcium and sulfide, respectively. Reduction of the precipitated CaSO 4 into CaS was carried out at 550°, 750°, 950°, and 1150°C at a flow rate of H 2 5 mL/min and N 2 95…
Perovskite lead strontium titanate solid solution phase has been crystallized in the presence of La2O3 in the system [(PbxSr1−x)O∙TiO2]–[2SiO2∙B2O3]–[K2O]–[BaO]–[La2O3] (1⩽x⩽0.5). La2O3 is a donor dopant for (Pb,Sr)TiO3 and can make crystalline phase semiconducting in the glass ceramics. Dispersion of semiconducting p…
Abstract Summary: The first example of the synthesis of acrylonitrile copolymers with porphyrin pendants and the subsequent electrospinning of the resultant copolymers into nanofibers is presented in this communication. Vinyl porphyrin monomers have been synthesized and copolymerized with acrylonitrile through solutio…
The background and use of dual-space direct methods for the ab initio phasing of small macromolecules as well as the phasing of heavy-atom substructures of larger biological structures are described. Basic concepts include normalized structure factors, multisolution procedures, random trial structures, phase-refinemen…
Abstract Summary: A series of methacrylate copolymers containing polyhedral oligomeric silsesquioxane (POSS) was synthesized from the free radical copolymerization of methacrylic acid, methyl methacrylate, and isobutyl propylmethacryl polyhedral oligosilsesquioxanes, and then were modified with glycidyl methacrylate t…