Materials Literature
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We present a systematic method of constructing limit-quasiperiodic structures with non-crystallographic point symmetries. Such structures are different aperiodic ordered structures from quasicrystals, and we call them "superquasicrystals". They are sections of higher-dimensional limit-periodic structures constructed o…
Superconductor-Ferromagnet-Superconductor (S-F-S) Josephson junctions were fabricated by making a narrow cut through a S-F double layer using direct writing by Focused Ion Beam (FIB). Due to a high resolution (spot size smaller than 10 nm) of FIB, junctions with a small separation between superconducting electrodes ($…
A multiple-tip ultra-high vacuum (UHV) scanning tunneling microscope (MT-STM) with a scanning electron microscope (SEM) for imaging and molecular-beam epitaxy growth capabilities has been developed. This instrument (nanoworkbench) is used to perform four-point probe conductivity measurements at micrometer spatial dime…
Polyhedral oligomeric silsesquioxane (POSS), a hybrid nanostructured macromer has been used in the last decade for preparation of polymeric nanocomposites. Its versatile chemistry, which lends it for almost infinite chemical modification, sets it apart from other nanostructured fillers like nanoclays, carbon nanotubes…
Some double space tensorial quantities in the nonlinear theory of dislocations are considered. Their real space counterparts are introduced.
Using the simplest two-subband Stoner model, it is shown that the variation of the Fermi energy under applied magnetic field is inverse proportional to the spontaneous magnetization and hence most pronounced close to the critical Stoner condition, that is to the quantum critical point of ferromagnetic transition. The…
A technology is reviewed which allows one to produce quasi-lateral 2D electron and hole gas junctions of arbitrary shape. It may be implemented in a variety of semiconductor heterostructures. Here we concentrate on its realization in the GaAs/AlGaAs material system and discuss the possibility to use this structure for…
A first-principles-derived approach is developed to study the effects of depolarizing electric fields on the properties of Pb(Zr,Ti)O3 ultrathin films for different mechanical boundary conditions. A rich variety of ferroelectric phases and polarization patterns is found, depending on the interplay between strain and t…
Concerns about emissions of carbon dioxide have created a need to develop more fuel‐efficient vehicles. Diesel engines are generally more efficient than gasoline engines but improvements in the latter can be achieved by operating under lean‐burn conditions. With both diesel and lean‐burn gasoline engines, the nitrogen…
UV/vis/NIR absorbance spectra were used to monitor electron transfer between small-molecule redox reagents and carbon nanotubes (CNTs). The oxidation of (6, 5)-enriched nanotubes in water with K(2)Ir(Cl)(6) reveals a valence electron density of 0.2-0.4 e(-)/100 carbon atoms and a reduction potential of approximately 8…
This paper reviews the recent progress made in the asymmetric synthesis on chiral catalysts in porous materials and discusses the effects of surface and pores on enantioselectivity (confinement effect). This paper also summarizes various approaches of immobilization of the chiral catalysts onto surfaces and into pores…
A section method for projected structures of icosahedral quasicrystals (IQCs) is given. A structure projected along a specified direction can be calculated directly from a six-dimensional periodic structure by this method. The method concludes that all peaks in high-resolution transmission electron-microscopy images o…
In this work, a novel two-step construction strategy for protein layer-by-layer assembly films was proposed. In the first step, positively charged hemoglobin (Hb) or myoglobin (Mb) at pH 5.0 was adsorbed on the negatively charged surface of 500 nm diameter-sized polystyrene (PS) latex beads, forming core-shell structu…
The network structures of polyhedral oligomeric silsesquioxane based nanocomposites are studied by continuous-space Monte Carlo simulations. The nanoporous network contains intercubic pores and mesopores which can be clearly identified in this work. In terms of degree of cross linking and pore size distribution (PSD),…
Neutron-induced fission cross-section ratios $^{\mathrm{nat}}\mathrm{Pb}∕^{209}\mathrm{Bi},\phantom{\rule{0.2em}{0ex}}^{208}\mathrm{Pb}∕^{209}\mathrm{Bi},\phantom{\rule{0.2em}{0ex}}^{197}\mathrm{Au}∕^{209}\mathrm{Bi},\phantom{\rule{0.2em}{0ex}}^{\mathrm{nat}}\mathrm{W}∕^{209}\mathrm{Bi},\phantom{\rule{0.2em}{0ex}}^{18…
Micro-Raman spectroscopy, infrared absorption microspectroscopy, and AFM images of nano- or microsized micelles formed by fulvic acid (FA) solutions, prepared at different pHs, and cast on glass slides or gold island films, are reported. FA films cast on gold islands are characterized by surface-enhanced infrared abso…
A new superconducting sodium cobalt oxide (see Figure, left) has been synthesized through soft-chemical modification using α-NaCoO2 as a parent compound, in place of the γ-Na0.7CoO2 used to make the first cobalt oxide superconductor (see Figure, right). A three-layer periodicity of the CoO2 stacking sequence exists in…
At a lattice-matched ZnO/ScAlMgO4 heterointerface, Hall and field-effect mobilities of grain-boundary-free ZnO channels have been simultaneously characterized under a gate electric field (EG) applied through a ScAlMgO4 dielectric gate. The field-effect mobility increased linearly with increasing EG (see Figure), clear…
Abstract In this work, preparation and properties of different nanoclays modified by organic amines (octadecyl amine, a primary amine, and hexadecyltrimethylammonium bromide, a tertiary amine) and brominated polyisobutylene‐ co ‐paramethylstyrene (BIMS)‐clay nanocomposites are reported. The clays and the rubber nanoco…
Ferroelectricity can be detected in systems consisting of liquid‐crystalline monomer–polymer mixtures possessing no chiral centers The ferroelectric behavior in mixtures of achiral liquid‐crystalline side‐chain polymers and achiral liquid‐crystalline monomers is reported for the first time. The mixtures manifested hig…