Materials Literature
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The acoustic phonon-mediated drag-contribution to the drag current created in the ballistic transport regime in a one-dimensional nanowire by phonons generated by a current-carrying ballistic channel in a nearby nanowire is calculated. The threshold of the phonon-mediated drag current with respect to bias or gate volt…
A numerical scheme for solving the time-evolution of wave functions under the time dependent Kohn-Sham equation has been developed. Since the effective Hamiltonian depends on the wave functions, the wave functions and the effective Hamiltonian should evolve consistently with each other. For this purpose, a self-consis…
Transport in molecular electronic devices is different from that in semiconductor mesoscopic devices in two important aspects: (1) the effect of the electronic structure and (2) the effect of the interface to the external contact. A rigorous treatment of molecular electronic devices will require the inclusion of these…
The doping of the manganese site by iridium (up to 15%) in the small A cation manganites Pr_{1-x}Ca_xMnO_3 (0.4 < x < 0.8), has been investigated as a new method to suppress charge-ordering and induce CMR effects. Ir doping leads to ferromagnetism and to insulator to metal transitions, with high transition temperature…
CO adsorption on the Pt(111) surface is studied using first-principles methods. As found in a recent study [Feibelman, et al., J. Phys. Chem. B 105, 4018 (2001)], we find the preferred adsorption site within density functional theory to be the hollow site, whereas experimentally it is found that the top site is prefer…
Left-handed materials are studied numerically using an improved version of the transfer-matrix method. The transmission, reflection, phase of reflection, and absorption are calculated and compared with experiments for both single split-ring resonators with negative permeability and left-handed materials, which have bo…
A sharp collective charge excitation is predicted in MgB$_2$ at $\sim2.5eV$ for $q$ perpendicular to the boron layers, based on an all-electron analysis of the dynamical density response within time-dependent density functional theory. This novel excitation, consisting of coherent charge fluctuation between Mg and B s…
The recently discovered (1 x 4) reconstruction of the stoichiometric anatase TiO(2)(001) surface is studied via first principles density functional calculations. We propose a new structural model for this reconstruction, which is energetically much more favorable than all the other available models, including the unre…
We review recent advances in experimental methods for high spatial-resolution and high time-resolution thermometry, and the application of these and related methods for measurements of thermal transport in low-dimensional structures. Scanning thermal microscopy (SThM) achieves lateral resolutions of 50 nm and a measur…
The frequency dependence of the shear modulus was studied for cross-linked polyurethane melts and gels at various cross-link densities. The polyurethane used in this study was based on mixtures of bifunctional linear poly(propylene oxide) (PPO) and trifunctional star PPO end-linked with diisocyanate. The connectivity…
Ultrathin bimetallic Au/Ni films vapor-deposited on yttria-stabilized ZrO 2 (100) (YSZ) were characterized by X-ray and UV photoelectron spectroscopy (XPS, UPS) at 300 and 570 K and by temperature-programmed desorption of CO (TPD). Photoemission results indicate that, upon co-deposition of the two metals, the Ni signa…
We consider here small-length-scale crystal structures with two clearly different molecular components (e.g., hydrophobic and hydrophilic). Using a perspective developed by studies on large-length-scale block copolymers and liquid crystals, we focus on the crystalline interface between the two components. We examine f…
Electrooxidation of tetrathiafulvalene (TTF) carried out in the presence of (Bu4N)2TTF(CO2H)2(CO2)2 as supporting electrolyte affords wholly TTF organic materials in which TTF cations are associated with TTF(CO2H)2(CO2−)2 as counteranions.
We describe a method that explains the morphology of needle-shaped crystals by analyzing the growth mechanisms for the various crystal faces, the relevant parameter being the edge free energy of a two-dimensional nucleus on a surface. As an example, the crystal morphology of a β‘ triacylglycerol is chosen. The results…
Amine-terminated polyamidoamine (PAMAM) dendrimers can be immobilized onto anhydride-functionalized pulsed plasma polymer surfaces via amide linkage formation. The packing density of dendrimers at the surface can be tailored by programming the pulse duty cycle parameters during plasma polymerization. These PAMAM dendr…
L-Lactate dehydrogenase (LDH) from Lactobacillus pentosus is a non-allosteric enzyme, which shows, however, high sequence similarity to allosteric LDHs from certain bacteria. To elucidate the structural basis of the absence of allostery of L. pentosus LDH (LPLDH), we determined the crystal structure of LPLDH at 2.3 A…
We have investigated the attachment of recently developed poly(ethylene glycol)−poly( dl -lactic acid) (PEG−PLA) copolymeric micelles onto functionalized TiO 2 and Au. The attachment and immobilization of the micelles were investigated via X-ray photoelectron spectroscopy and reflection−absorption infrared spectroscop…
We describe the growth of magnetic nanostructures on carbon nanotube templates. The nanotubes were grown by microwave plasma enhanced chemical vapor deposition. The as-grown nanotubes were aligned reasonably well around the substrate normal directions. However, it was found that the nanotubes grown on magnetic catalys…
The early interdiffusion stages in epitaxially grown Ag/Au and Cu/Au reaction couples are investigated by high-resolution and Z-contrast electron microscopy. While the interdiffusion in the lattice-matched system Ag/Au follows Fick's diffusion laws from the very beginning, a complex two-stage reaction is observed in t…
We describe a constant-traction molecular dynamics method to perform simulations of a generic atomistic system under an applied external load. The main objective is to ensure consistency between the atomistic model and the macroscopic continuum-mechanics description. Examples of simulations for different kinds of exte…