Materials Literature
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Using density matrix equations of motion, we predict a femtosecond collective spin tilt triggered by nonlinear, near-ultraviolet (approximately 3 eV), coherent photoexcitation of (Ga,Mn)As ferromagnetic semiconductors with linearly polarized light. This dynamics results from carrier coherences and nonthermal populatio…
The influence of nanoparticles on the domain orientation in a particle co-operated self-assembly process in thin diblock copolymer films is investigated toward the preparation of ordered magnetic nanoparticle arrays. Thin films are prepared from a mixture of chemically masked iron oxide nanoparticles and a polystyrene…
Surface-enhanced Raman optical activity (SEROA) is investigated theoretically for molecules near a metal nanoshell. For this purpose, induced molecular electric dipole, magnetic dipole, and electric quadrupole moments must all be included. The incident field and the induced multipole fields all scatter from the nanosh…
The potential applications of dispersive kinetic models range from solid-state conversions to gas-phase chemical physics and to microbiology. Here, the derivation and application of two such models, for use in solid-state applications, is presented. The models are based on the concept of a Maxwell-Boltzmann distributi…
The effects of pressure generated in a liquid-medium clamp pressure cell on the in-plane and $c$-axis resistance, temperature-dependent Hall coefficient, and low-temperature magnetoresistance in ${\text{CaFe}}_{2}{\text{As}}_{2}$ are presented. The $T\ensuremath{-}P$ phase diagram, including the observation of a compl…
The longitudinal acoustic (LA) phonon of a ${\text{Ba}}_{088}{\text{K}}_{0.12}{\text{TiO}}_{2.88}{\text{F}}_{0.12}$ perovskite crystal was investigated through micro-Brillouin scattering measurements to clarify the effect of KF substitution in ${\text{BaTiO}}_{3}$ on the dynamical properties related to the ferroelectr…
A new real-space numerical implementation of the self-consistent field theory for semiflexible polymers is developed. Specifically, a finite volume algorithm on a unit sphere with an icosahedron triangular mesh is employed to describe the orientation degree of freedom of the wormlike chains. The validity of the new me…
Abstract In this work we report on some aspects of the chemistry of the organic electron‐donor 1,2,4,5‐tetrakis(tetramethylguanidino)benzene (ttmgb). Reactions with electron acceptors and proton donors as well as late transition metals to give binuclear complexes (including a binuclear Cu II complex with antiferromagn…
The effect of core−shell polymer-coated nanoparticles on block copolymer morphology is investigated systematically by controlling particle positioning within a block copolymer template. Our approach of varying the areal chain density (Σ) of short thiol terminated polystyrene (PS-SH) brushes on the particles where the…
Polyamidoamine (PAMAM) dendrimers of generation 6-4, G-5 and G-6 were evaluated for their aquatic toxicity using the test models Vibrio fischeri, Daphnia magna, Thamnocephalus platyurus, and two fish cell lines. Physico-chemical characterization of the particles in each of the different test media was performed. A sig…
We present a density-functional theory study of finite-size effects in stoichiometric and nonstoichiometric ${\text{BaTiO}}_{3}$ nanowires of varying cross-sectional sizes and sidewall terminations. The tendencies for axial, transverse, and toroidal ferroelectric polarization instabilities in these nanowires have been…
We describe the direct observation of entropy-driven crystallization in simulations of dense packings of linear hard-sphere chains. Crystal nuclei form spontaneously in the phase coexistence region independently of chain length. Incipient nuclei consistently develop well defined, stack-faulted layered morphologies wit…
Abstract The photoluminescence properties of different pristine CeO 2 specimens (bulk crystal, film, and nanocrystals) have been studied at different temperatures between 7 K and room temperature. The photoinduced luminescence spectral change has been observed at room temperature for the first time. The phenomenon obs…
Spatial dimensionality affects the degree of confinement when an electron-hole pair is squeezed from one or more dimensions approaching the bulk exciton Bohr radius (a(B)) limit. The electron-hole interaction in zero-dimensional (0D) dots, one-dimensional (1D) rods/wires, and two-dimensional (2D) wells/sheets should b…
The formation and full characterization of single self-assembling alpha,gamma-peptide nanotubes (alpha,gamma-SPNs) is described. The introduction of C(60) into cyclic peptides allows the preparation of supramolecular 1D fullerene arrangements induced by peptide nanotube formation under appropriate conditions.
The reduction of structural Fe in smectite may be mediated either abiotically by reaction with chemical reducing agents or biotically by reaction with various bacterial species. The effects of abiotic reduction on clay surface chemistry are much better known than the effects of biotic reduction, and differences betwee…
We investigate the time-dependent linear viscoelastic behavior of amine and alkaline metal-neutralized carboxy−telechelic 1,4-polybutadiene, and compare it with the acid precursor as well as an ester end-modified version. The ionic groups form aggregates with a aggregate spacing period around 85 Å, containing about 90…
We present hydrolytically degradable polymeric multilayer films that can codeliver multiple therapeutics of differing chemical characteristics (charged biomacromolecules and neutral hydrophobic small molecules) from a surface. This multiagent-delivery (MAD) nanolayer system integrates the hydrolytically degradable pol…
Surface plasmon polariton reflector (SPPR) based on metal-insulator-metal (MIM) Bragg grating waveguide is numerically studied. A quasi-chirped technique is applied to the engraved grooves in the surface of the MIM waveguide, and a new kind of broad-bandgap SPPR is achieved. Meanwhile, by optimizing the profile of gap…
Molecular dynamics modeling shows that multiwall carbon nanotubes (MWCNTs) with sp;{3} interwall bonding have strengths exceeding those of single-wall carbon nanotubes (SWCNTs) containing the same size initial intrawall defect, and are far less sensitive to defect size. Thus, although processing methods used to increa…