Materials Literature
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The solidification structures of cast Fe-B-C alloy containing more than 2.0%B and lower than 0.2%C and the structures and properties of alloy after heat treatment were researched by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), hardness measurements, impact tester and p…
We present simulations on a binary blend of bead-spring polymer chains. The introduction of monomer size disparity yields very different relaxation times for each component of the blend. Competition between two different arrest mechanisms, namely, bulklike dynamics and confinement, leads to an anomalous relaxation sce…
Textured (1‐ x )(Mg 1/3 Nb 2/3 )O 3 – x PbTiO 3 (PMN–PT) ceramics obtained by the templated grain growth process possess a significant fraction of the piezoelectric properties of Bridgman‐grown single crystals at a fraction of the cost. However, for integration of these materials into transducer and actuator designs,…
Abstract A series of novel composites and nanocomposites xerogels based on acrylic acid, sepiolite and N , N ′‐methylenebisacrylamide were prepared using a solution polymerization technique at 70 °C. The quality of dispersion of the micronized sepiolite in the monomer is the crucial point for obtaining nanocomposites.…
The synthesis and spectroscopic characterization of a series of luminescent platinum meso-tetrakis{3,5-di[(N-carbazyl)n-alkyloxyphenyl]}porphyrin (Pt-8Cn-TPP, n-alkyl = (CH2)n, n = 4, 6, and 8) are presented. The protonated platinum porphyrins ([Pt-8Cn-TPPH8]8+) were assembled with mesoporous silica MCM-48 resulting i…
Experimental and computational results for the two-step redox system [Cl5Os(NO)]n- (n = 1-3) are reported and discussed in comparison to the related one-step redox systems [Cl5Ru(NO)]n- and [Cl5Ir(NO)]n- (n = 1, 2). The osmium system exhibits remarkably low oxidation and reduction potentials. The structure of the prec…
CO adsorption on small neutral, anionic, and cationic silver clusters Ag(n) (n = 1-7) has been studied with use of the PW91PW91 density functional theory (DFT) method. The adsorption of CO on-top site, among various possible sites, is energetically preferred irrespective of the charge state of the silver cluster. The…
The use of nanotechnology in consumer and industrial applications will likely have a profound impact on a number of products from a variety of industrial sectors. Nanomaterials exhibit unique physical/chemical properties and impart enhancements to engineered materials, including better magnetic properties, improved el…
This paper discusses the effect of uniaxial compressive stress and pressureless constraint on the microstructure, density, and shrinkage anisotropy during the sintering of two commercial low‐temperature co‐fired ceramic (LTCC) systems, i.e., Heraeus CT2000 (CT) and DuPont 951Tape (DU). Under uniaxial compression, the…
The viscoelastic and viscoplastic behaviors of high density polyethylene (HDPE) under uniaxial monotonic and cyclic loading are modeled using the modified viscoplasticity theory based on overstress (VBO). The viscoelastic modeling capabilities of the modified VBO are investigated by simulating the behavior of semicrys…
Magnetic hybrid hollow spheres of about 200 nm were prepared by a core-template-free route, that is, adding Fe3O4 nanoparticles stabilized by poly(vinyl alcohol) (PVA) to an aqueous solution of polymer-monomer pairs composed of a cationic polymer, chitosan (CS), and an anionic monomer, acrylic acid (AA), followed by p…
The electron and hole relaxation in the (7, 0) zigzag carbon nanotube is simulated in time domain using a surface-hopping Kohn-Sham density functional theory. Following a photoexcitation between the second van Hove singularities, the electrons and holes decay to the Fermi level on characteristic subpicosecond time sca…
The effects of flexibility and chemical composition in the variation of the glass transition temperature are obtained by using the Lindemann criteria, which relates melting temperature with atomic vibrations, and rigidity theory. Using this criteria and that floppy modes produce an excess of vibrational states at low…
Using Monte Carlo simulations within the empirical potential approach, we examine the effect produced by the surface environment on the atomic level stresses in tetrahedral amorphous carbon. Both the distribution of stresses and the distributions of sp^2 and sp^3 atoms as a function of depth from the surface are highl…
We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate…
YBaCo4O7 belongs to a new class of geometrically frustrated magnets like the pyrochlores, in which Co-spins occupy corners of tetrahedra. The structure can be viewed as an alternating stacking of Kagome and triangular layers. Exactly half of the triangular units of the Kagome plane are capped by Co ions to form column…
As devices are reduced in size, interfaces start to dominate electrical transport making it essential to be able to describe reliably how they transmit and reflect electrons. For a number of nearly perfectly lattice-matched materials, we calculate from first-principles the dependence of the interface transparency on t…
Abstract The effects of expandable graphite (EG) of different particle sizes, on the fire‐retardant properties of high‐density rigid polyurethane foam (RPUF) (0.45 g cm −3 ) were studied. Samples of EG with different particle sizes were obtained by pulverization in an ultra‐high‐speed mixer for 4 and 13 min, respectiv…
The aim of this Chapter is to provide an account of recent advances in the first-principles modeling of ferroelectric oxide nanostructures. Starting from a microscopic description of ferroelectricity in bulk materials and considering then, successively, different kinds of nanostructures (films, multilayers, wires, and…
This report describes the preparation and characterization of new magnetic fluorescent nanoparticles and our success in using them to label living cells. The bifunctional nanoparticles possess a magnetic oxide core composed of a dimercaptosuccinic acid (DMSA) ligand at the surface and a covalently attached fluorescent…