Materials Literature
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Thin films with cobalt ferrite layers on thermally oxidized silicon wafers were fabricated by a sol-gel method. Magnetic and structural properties of the films were investigated with an x-ray diffractometer, a vibrating sample magnetometer and atomic force microscopy. The crystallization temperature for Co ferrite thi…
We show that a finite interface thickness in an isothermal phase-field model for alloy solidification introduces a chemical potential gradient in the interfacial region and the solute trapping effect, and the relationships between material properties and parameters in the phase-field equation can be determined at a lo…
Surface enhanced Raman scattering (SERS) is being increasingly used for the study of the structural properties of conducting polymer thin films. It is generally accepted that the enhancement process has an electromagnetic origin, arising from the excitation of surface plasmons in the metal support on which the polymer…
We have investigated the nature of epitaxy, defects (dislocations, stacking faults, and inversion domains), and heterointerfaces in zinc oxide films grown on (0001) sapphire and explored the possibility of using it as a buffer layer for growing group III nitrides. High quality epitaxial ZnO films were grown on sapphir…
We study the problem of atomic scale fracture using the recently developed quasicontinuum method in which there is a systematic thinning of the atomic-level degrees of freedom in regions where they are not needed. Fracture is considered in two distinct settings. First, a study is made of cracks in single crystals, and…
A review is given on the basic properties of 2:14:1 hard magnetic phases as well as technological procedures used for manufacturing R-Fe-B and R-Fe-C permanent magnets. First, we analyse the phase diagrams, crystal structure of hard magnetic phases and composition ranges in which these phases form solid solutions, as…
We describe a tellurite-based Er/sup 3+/-doped fiber amplifier (EDFA) with a flat amplification bandwidth of 76 nm and a noise figure of less than 7 dB. Furthermore, a parallel-type amplifier composed of this EDFA and a 1.45-μm-band Tm/sup 3+/-doped fluoride fiber amplifier achieved a flat amplification bandwidth of 1…
The crystalline swelling properties and interlayer structure of a cesium montmorillonite clay were investigated using molecular computer simulations. Two classes of dry-clay structures, proposed previously to explain X-ray diffraction and NMR experiments, were identified using Monte Carlo annealing calculations. Hydra…
During rapid solidification, solute may be incorporated into the solid phase at a concentration significantly different from that predicted by equilibrium thermodynamics. This process, known as solute trapping, leads to a progressive reduction in the concentration change across the interface as the solidification rate…
The synthesis of tailored nanoparticles—non-porous and porous—is a major challenge in advanced materials science. The authors here report the synthesis of submicrometer-size silica particles with a solid core and a thin porous shell (see Figure). The thermal stability and the high specific surface area make these sili…
To compare the heat responses of mechanically sensitive and mechanically insensitive A-fiber nociceptors, an electrical search technique was used to locate the receptive fields of 156 A-fibers that innervated the hairy skin in the anesthetized monkey (77 A beta-fibers, 79 A delta-fibers). Two-thirds of these afferents…
Summary Organic acids have been implicated in many soil‐forming and rhizosphere processes, but their fate in soil is poorly understood. We examined the sorption of four simple short‐chain organic acids (citric, oxalic, malic and acetic) in five acid soils and on synthetic iron hydroxide (ferrihydrite). The results for…
Amorphous precipitates of CaCO3 were prepared by reacting a mixed solution of Na2CO3–NaOH with a CaCl2 solution at various pH (≥11.2) at an ambient temperature of 278 K. The precipitates prepared at pH ranging from 11.2 to 13.0 were identified as amorphous calcium carbonate (ACC) by means of TG–DTA, FT-IR spectroscopy…
Intermediate Temperature Solid Oxide Fuel Cells Using a New LaGaO3 Based Oxide Ion Conductor: I. Doped SmCoO3 as a New Cathode Material, Ishihara, Tatsumi, Honda, Miho, Shibayama, Takaaki, Minami, Hiroaki, Nishiguchi, Hiroyasu, Takita, Yusaku
The shape-memory effect is a solid state phenomenon which exploits a reversible phase transformation to repeatedly achieve an initial shape, even after some deformation of the material. Numerous metal alloys exhibit this effect. One of the most widely used shape-memory alloys is TiNi, due to its large range of recover…
To investigate the metabolic link between fatty acid de novo synthesis and polyhydroxyalkanoic acid (PHA) synthesis, we isolated mutants of Pseudomonas putida KT2440 deficient in this metabolic route. The gene phaG was cloned by phenotypic complementation of these mutants; it encoded a protein of 295 amino acids with…
Porous thin-film dielectric insulators with significantly lower dielectric constants are expected to have great impact on the fabrication of ever smaller semiconductor devices and chips with higher packaging densities. Here two routes to the preparation of such nanoporous thin films are presented. A method has been de…
The novel organometallic−inorganic diblock copolymer, poly(ferrocenyldimethylsilane)- b -poly(dimethylsiloxane) (PFS- b -PDMS) (block ratio = 1.0:6.0) ( M n = 35 100 g/mol with a narrow molecular weight distribution M w / M n = 1.10 based upon gel permeation chromatography in THF using polystyrene standards) forms lon…
An improved cathode material for a solid‐oxide fuel cell would be a mixed electronic and oxide‐ion conductor with a good catalytic activity for oxygen reduction at an operating temperature T op ≥ 700°C and a thermal expansion matched to that of the electrolyte and interconnect. We report on the properties of Sr‐ and N…
Crystallization of mesoscale particles by a simple and general methodology is reported here. The versatility of this method is demonstrated by the production of monolayers, bilayers, and multilayers of polystyrene beads (see the scanning electron micrograph shown in the Figure). The method is useful, for example, for…