Materials Literature
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New nanoparticles based on well-defined dextran esters were prepared by a dialysis process. Dextran was converted into a propionate with a degree of substitution of 1.70 and, subsequently, acylated under homogeneous reaction conditions with a pyroglutamic acid imidazolide, which is prepared in situ by conversion of py…
We present two-terminal magnetotransport measurements on single-wall carbon nanotube devices, where one or two of the terminals are ferromagnetic. Both ferromagnetic semiconductor [(Ga,Mn)As] and metal (Fe) contact materials have been investigated. In both types of devices we have observed strong hysteretic magnetores…
Multiferroic laminated composites consisting of Terfenol-$D$/polyvinylidene-fluoride (PVDF) and lead-zirconate titanate (PZT)/PVDF particulate composite layers were prepared by a simple hot-molding technique. Magnetoelectric coefficients are characterized for the different measuring angles between the directions of po…
We study a lattice model for mode III crack propagation in brittle materials in a stripe geometry at constant applied stretching. Stiffening of the material at large deformation produces supersonic crack propagation. For large stretching the propagation is guided by well developed soliton waves. For low stretching, th…
We report the structural and magnetoelectrical properties of La0.7Ca0.3MnO3∕BaTiO3 perovskite superlattices grown on (001)-oriented SrTiO3 by the pulsed laser deposition technique. Magnetic hysteresis loops, together with temperature dependent magnetic properties, exhibit well-defined coercivity and magnetic transitio…
We present experiments on the doublon growth morphology in directional solidification. Samples used are succinonitrile with small amounts of poly(ethylene oxide), acetone, or camphor as the solute. Doublons, or symmetry-broken dendrites, are generic diffusion-limited growth structures expected at large undercooling an…
From sea urchin teeth to mammalian bones, the skeletons of organisms often contain several levels of structural hierarchy, designed to resist mechanical damage. In his Perspective, Currey describes several such hierarchical systems, highlighting in particular the high level of hierarchical organization in the skeleton…
This chapter aims at identifying what is specific to femtosecond laser ablation. It reviews the essential basic processes which contribute to femtosecond laser ablation of various materials : energy absorption by the material's electrons, electronic relaxation processes involving either electron-electron or electron-l…
The first- and second-order magnetoelastic coefficients of the metastable bcc phases Co and Ni are calculated by using a combination of the phenomenological theory of nonlinear magnetoelasticity with the ab-initio density functional electron theory. The magnetoelastic behavior of the bcc phases is drastically differen…
Nanocrystals of the wide band gap semiconductor zinc oxide of controllable morphologies were synthesized by a simple thermal decomposition method. The predominating factor in determining the morphology (spheres, triangular prisms, and rods) was the solvent, selected on the basis of coordinating power. The nanoparticle…
Hydrogen is dissociatively adsorbed on the gold particles in Au/Al(2)O(3) catalysts, as demonstrated by a combination of in-situ X-ray absorption spectroscopy, chemisorption, and H/D exchange experiments. This chemisorption of hydrogen induces changes in the Au L(3) and L(2) X-ray absorption near-edge structures. The…
We have used variable cooling rate ellipsometric measurements to probe the slow dynamics in thin supported polystyrene films. For the slowest cooling rates (approximately 1 K/min) the measured Tg values are reduced below the bulk value with the measured Tg of 341 K for a 6 nm film. As the cooling rate is increased the…
We report studies of ferroelectricity in ultrathin perovskite films with realistic electrodes. The results reveal stable ferroelectric states in thin films less than $10\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$ thick with polarization normal to the surface. Under short-circuit boundary conditions, the screening effec…
A phase-field model that allows for quantitative simulations of low-speed eutectic and peritectic solidification under typical experimental conditions is developed. Its cornerstone is a smooth free-energy functional, specifically designed so that the stable solutions that connect any two phases are completely free of…
An organic material composed of neutral free radicals based on the spirobiphenalenyl system exhibits a room temperature conductivity of 0.3 siemens per centimeter and a high-symmetry crystal structure. It displays the temperature-independent Pauli paramagnetism characteristic of a metal with a magnetic susceptibility…
We investigate the jamming transition in packings of emulsions and granular materials via molecular dynamics simulations. The emulsion model is composed of frictionless droplets interacting via nonlinear normal forces obtained using experimental data acquired by confocal microscopy of compressed emulsions systems. Gra…
Structural materials in nature exhibit remarkable designs with building blocks, often hierarchically arranged from the nanometer to the macroscopic length scales. We report on the structural properties of biosilica observed in the hexactinellid sponge Euplectella sp. Consolidated, nanometer-scaled silica spheres are a…
A wide variety of experimental results and theoretical investigations in recent years have convincingly demonstrated that several transition metal oxides and other materials have dominant states that are not spatially homogeneous. This occurs in cases in which several physical interactions-spin, charge, lattice, and/o…
The title compound, pentabarium tris(vanadate) chloride, crystallizes in the well known apatite structure type, with space group P63/m and Z = 2. The crystal structure contains isolated (VO4)3− tetrahedra that are bridged by Ba2+ ions. The intermediate Cl− anions, situated on positions with \overline{3} symmetry,…
Previous in situ small-angle neutron scattering studies of nitrogen adsorption and desorption at 78 K on the mesoporous silica xerogels Gelsil 50 and Gelsil 75 revealed the formation of ramified clusters of vapor-filled pores on desorption, which is characteristic for a percolation process. In the present work, we che…