Materials Literature
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Both end-functionalized (alpha-bromo and omega-carboxy) compounds were first tested for the radical reaction on the silicon-hydride (Si-H) terminated porous silicon (PSi) with/without the presence of diacyl peroxide initiator under microwave irradiation. Then the carboxylic acid monolayers (CAMs) assembled on PSi thro…
Abstract A polylactide of high optical purity was crystallized between 100 and 140 °C, in‐between two glass slides, and its morphology was investigated by polarizing optical microscopy, scanning electron microscopy, and atomic force microscopy, during subsequent heating and cooling cycles between −15 °C and the crysta…
Despite widespread use for more than two decades, the SERS phenomenon has defied accurate physical and chemical explanation. The relative contributions from electronic and chemical mechanisms are difficult to quantify and are often not reproduced under nominally similar experimental conditions. This work has used elec…
Blends of poly( dl -lactide) (PDLLA) with poly(vinylphenol) (PVPh), obtained by solvent-casting and solution/precipitation, have been studied by DSC and FTIR. DSC results obtained in the first heating scan suggest that as-prepared blends are phase separated in nearly pure components. In addition, the initial FTIR spec…
Aluminum nitride (AlN) powders were synthesized by gas reduction–nitridation of γ‐Al 2 O 3 using NH 3 and C 3 H 8 as the reactant gases. AlN was identified in the products synthesized at 1100°–1400°C for 120 min in the NH 3 –C 3 H 8 gas flow confirming that AlN can be formed by the gas reduction–nitridation of γ‐Al 2…
It has long been a puzzle that the Raman optical modes shift to lower frequency (or termed optical mode softening or redshift) associated with the creation of Raman acoustic modes that shift to higher energy (or called acoustic hardening or blueshift) upon a nanosolid being formed and its size being reduced. Understan…
Two‐dimensional computer simulations of ferroelectric polarization switching have been performed using the phase field simulation model developed by employing the time‐dependent Ginsburg–Landau equations. The bulk‐free energy, polarization gradient energy, long‐range dipole–dipole electrostatic interactions, and elast…
The reorientation of defect dipoles and the drift of free charge carriers are the most prominent microscopic mechanisms under discussion to provoke the aging effect in ferroelectrics. These two mechanisms are contrasted taking into account the influence of grain boundaries in a polycrystalline material. For the drift…
Resistivity measurements and x-ray absorption near-edge structure spectroscopy were performed on single crystals of 0.2 mol % Cr-doped $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$, which exhibit an electrical-field-induced insulator-to-conductor transition with a resistive memory effect. The electrically conducting state…
By employing thionine as a sensitizing dye, we have succeeded in inducing silver nanoparticle formation in ethanol/toluene medium. The particle size increases with the duration of photolysis, thus providing a simple experimental parameter to control the particle size. The photoinduced transformations as probed by stea…
Patterned arrays of gold nanoparticles in two dimensions were prepared by the electron beam reduction and subsequent thermolysis of gold(I)−thiolate complexes on silicon surfaces. The array line widths are <50 nm and they are composed of small gold nanoparticles (average diameters from 2 to 4.5 nm). Variation in the e…
Ferroelectric Ba0.6Sr0.4TiO3 thin films with 2% Mn additional doping were grown on (001) MgO by pulsed laser deposition. The microstructural studies from x-ray diffraction and transmission electron microscopy indicate that the films are highly epitaxial with c-axis oriented and atomic sharp interface. Dielectric prope…
Single metal nanoparticles and nanoaggregates are known to emit intense bursts of surface-enhanced Raman scattering (SERS) in an intermittent on and off fashion. The characteristic "blinking" timescales range from milliseconds to seconds. Here we report detailed temperature dependence (both heating and cooling) and li…
The potential use of ZnO-based photonic and electronic devices has been demonstrated by the fabrication of prototype ultraviolet (UV) photodetector and field-effect transistor (FET) devices that contain films of p-type ZnO with arsenic as the p-type dopant. These p-type films have high crystalline quality and show lon…
{\it Ab initio} computational methods for electronic transport in nanoscaled systems are an invaluable tool for the design of quantum devices. We have developed a flexible and efficient algorithm for evaluating $I$-$V$ characteristics of atomic junctions, which integrates the non-equilibrium Green's function method wi…
Phonon heat conduction is one of the critical research areas for nanoelectronics. The thermal conductivity of silicon nanostructures is studied to gain insight into heat conduction in silicon and related semiconductors. We experimentally show that phonon-boundary scattering results in a significant reduction in the th…
NaNbO(3) powders with various particle sizes (ranging from 30 nm to several microns) and well-controlled stoichiometry were obtained through microemulsion-mediated synthesis. The effect of particle size on the phase transformation of the prepared NaNbO(3) powders was studied using X-ray powder diffraction, Raman spect…
A series of novel copolymer microparticles from 4-sulfonic diphenylamine (SDP) and 1,8-diaminonaphthalene (DAN) was facilely prepared by a chemically oxidative polymerization. The structures and properties of the microparticles were systematically characterized by several important techniques. The microparticles exhib…
The fragility of polymeric glass-forming liquids is calculated as a function of molecular structural parameters from a generalized entropy theory of polymer glass-formation that combines the Adam-Gibbs (AG) model for the rate of structural relaxation with the lattice cluster theory (LCT) for polymer melt thermodynamic…
The formula derived by Meir and Wingreen [Phys. Rev. Lett. {\bf 68}, 2512 (1992)] for the electron current through a confined, central region containing interactions is generalized to the case of a nonorthogonal basis set. As in the original work, the present derivation is based on the nonequilibrium Keldysh formalism…