Materials Literature
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Single‐crystalline α‐Si 3 N 4 nanowires were synthesized by thermal decomposition of a polysilazane preceramic polymer using FeCl 2 powders as catalyst. The nanowires, which are 20–40 nm in diameter and up to several mm in length, possess smooth surfaces and uniform diameters along the entire length and contain no det…
This paper reviews some recent advances in small‐angle X‐ray and neutron scattering methods and their application to address complex issues in ceramic systems of technological importance. It is shown how small‐angle scattering (SAS) can be applied to ceramic systems in order to extract statistically representative mic…
We provide a rigorous theoretical basis for the artificial magnetic activity of metamaterials near resonances. Our approach is a renormalization-based scheme that authorizes a completely general theory. The major result is an explicit expression of the effective permeability, in terms of resonant frequencies. The theo…
This report describes two related methods for decorating cowpea mosaic virus (CPMV) with luminescent semiconductor nanocrystals (quantum dots, QDs). Variants of CPMV are immobilized on a substrate functionalized with NeutrAvidin using modifications of biotin-avidin binding chemistry in combination with metal affinity…
We have conducted a series of experiments designed to measure the flashover strength of various azimuthally symmetric $45\ifmmode^\circ\else\textdegree\fi{}$ vacuum-insulator configurations. The principal objective of the experiments was to identify a configuration with a flashover strength greater than that of the st…
Elastic shear moduli measurements on Fe100−xGax (x=12–33) single crystals (via resonant ultrasound spectroscopy) with and without a magnetic field and within 4–300 K are reported. The pronounced softening of the tetragonal shear modulus c′ is concluded to be, based on magnetoelastic coupling, the cause of the second p…
Orthogonally branched single-crystalline magnesium oxide nanostructures were synthesized through a simple chemical vapor transport and condensation process in a flowing Ar/O(2) atmosphere. Other morphologies, such as cubes and nanowires, can also be obtained under different controlled conditions. The formation of diff…
We present a detailed analysis of the effective force between two smooth spherical colloids floating at a fluid interface due to deformations of the interface in an inhomogeneous pressure field. The results hold in general and are applicable independently of the source of the deformation provided the capillary deforma…
Heat conduction through molecular chains connecting two reservoirs at different temperatures can be asymmetric for forward and reversed temperature biases. Based on analytically solvable models and on numerical simulations we show that molecules rectify heat when two conditions are satisfied simultaneously: the intera…
Co-sputtering from two independent magnetron sources was used to prepare polymer–metal nanocomposite films. Both gradient films with increasing metal fraction and homogeneous composite films were produced from polytetrafluoroethylene (PTFE) and silver targets using a rotatable sample holder. The structure of the pure…
Photoluminescence properties of Pr-doped alkaline-earth titanates Pr 0.002 (Ca,Sr,Ba) 0.997 TiO 3 are investigated by emission, excitation, and diffuse reflectance spectra at room temperature. The intensities of red luminescence and absorption due to f − f transition of Pr 3+ ions increase in the order of Pr-doped cub…
Unstabilized polypropylene (PP) films having selective 13 C isotopic labeling were subjected to thermal aging at 50, 80, and 109 °C and to γ-irradiation at 24 and 80 °C. The oxidized films were examined using solid-state 13 C nuclear magnetic resonance (NMR) spectroscopy. Dramatic differences were found in the type an…
Alumina/yttrium aluminum garnet (YAG) eutectic rods of 1 mm in diameter were grown by the laser‐heated floating zone method at different rates to obtain microstructures with the same morphology but of very different domain size. The mechanical properties of the rods (hardness, toughness, strength) were measured at amb…
Terfenol-D/epoxy pseudo 1-3 composites were fabricated by embedding and aligning Terfenol-D particles with a size distribution of 10–300μm in a passive epoxy matrix using six Terfenol-D volume fractions (υf) ranging from 0.22 to 0.72. The dependence of the dynamic relative permeability (μr33T), elastic modulus (E3H),…
Poly(butylene succinate) (PBSU) can be easily synthesized by condensation polymerization of the starting materials of succinic acid and butan-1,4-diol. It has good degradability and possesses excellent processability. Due to these advantages, PBSU was first evaluated in the present study for its potential application…
The effect of oxygen adsorption on a nanotube-based field effect transistor have been controversial as to whether it induces p-type doping of the nanotube body or the work function increase in the metal electrode. Here we report a transport measurement showing that a long individual single-walled nanotube can be doped…
We study the orbital and spin configurations of up to six electrons or holes charged into self-assembled InAs/GaAs quantum dots via single-particle pseudopotential and many-particle configuration interaction method. We find that while the charging of {\it electrons} follows both Hund's rule and the Aufbau principle, t…
Semiclassical equations of lasing dynamics are re-derived for a lasing medium in a cavity with a spatially non-uniform dielectric constant. It is shown that the non-uniformity causes a radiative coupling between modes of the empty cavity. This coupling results in a renormalization of self- and cross-saturation coeffic…
5% negative magnetoresistance (MR) at room temperature has been observed in bulk Ni2+xMn1−xGa. This indicates the possibility of using Ni2+xMn1−xGa as magnetic sensors. We have measured MR in the ferromagnetic state for different compositions (x=0–0.2) in the austenitic, premartensitic, and martensitic phases. MR is f…
Recent magnetic measurements on molecular magnets [Ni(hmp)(ROH)Cl]4, where RCH3, CH2CH3, or (CH2)2C(CH3)3, and hmp is the monoanion of 2-hydroxymethylpyridine, revealed a strong exchange bias prior to the external magnetic-field reversal as well as anomalies in electron paramagnetic-resonance peaks at low temperature…