Materials Literature
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We have developed a novel surface coating for semiconductor quantum dots (QDs) based on a heterobifunctional ligand that overcomes most of the previous limits of these fluorescent probes in bioimaging applications. Here we show that QDs capped with bidentate zwitterionic dihydrolipoic acid-sulfobetaine (DHLA-SB) ligan…
Ca/Na montmorillonite and natural Wyoming bentonite (MX-80) have been studied experimentally and theoretically. For a clay system in equilibrium with pure water, Monte Carlo simulations predict a large swelling when the clay counterions are monovalent, while in presence of divalent counterions a limited swelling is ob…
Abstract Excavated archaeological silver objects often exhibit extended intergranular degradation. This failure is most probably caused by the localised corrosion of highly copper‐segregated grain boundaries in case of a AgCu base alloy during burial for more than 1000 years in graves. Detailed electron backscatter d…
Abstract We have analyzed spin quenching of first row transition metals deposited on (001) defect‐free and defect‐containing surfaces of MgO insulator and CdO semiconductor by means of density functional calculations and embedded cluster model. Clusters of moderate sizes were embedded in the simulated Coulomb fields t…
The maximum entropy method (MEM) has been used to determine electron density in superspace of incommensurately modulated chromium pyrophosphate from X-ray diffraction data measured by Palatinus et al. [(2006), Acta Cryst. B62, 556-566]. Chromium pyrophosphate, Cr(2)P(2)O(7), contains ordered regions (83% of the volume…
Abstract We studied the Seebeck coefficient S of sputtered Zn 0.98 Al 0.02 O samples with free carrier concentrations varying from 10 18 to 10 21 cm –3 . The temperature dependence of the Seebeck coefficient at low carrier concentrations exhibits typical semiconductor behavior (S < 0 and pronounced phonon drag belo…
Combustion synthesis of Ti 3 SiC 2 /TiC composites from 3Ti/ x Si/2C ( x =1, 1.1, 1.2) powders was conducted under high‐gravity conditions with gravity up to 895 G. The results showed that the phase composition of the products strongly depended on the gravity level. We find that high‐gravity synthesis favors the growt…
Abstract This study reports surface characterizations of Pd/LaFeO 3 catalysts after aging in diesel engine simulated conditions. Thermal aging and support‐induced effects on the nature of Pd species were investigated. LaFeO 3 was prepared via a sol–gel method to promote relatively high specific surface area (19 m 2 g…
We demonstrate that excitons in semiconductor alloys are subject to competing localization effects due to disorder (random potential fluctuations) and shallow point defects (impurities).The relative importance of these effects varies with alloy chemical composition, impurity activation energy as well as temperature.We…
We describe here the facile methods for the stepwise regulation of the formation of tetrathiafulvalene (TTF) radical cation and the self-assembly to the mixed-valence state of TTF in various polymer films. The homogeneous polymer composites containing TTF and (1R)-3,3-dimethylbicyclo[2.2.1]hepta-2-one-1-triflate as a…
The ground-state structure, equilibrium structural parameters, electronic structure, and thermodynamical properties of MCaH(3) (M=Li, Na, K, Rb, and Cs) phases have been investigated. From the 104 structural models used as inputs for structural optimization calculations, the ground-state crystal structures of MCaH(3)…
We propose a class of antireflecting structures that can effectively suppress reflections for binary diffractive optics. In this structure, multiple periodic thin films with gradually varying refractive indices are used to shift all reflected diffraction to the transmitted orders. The structure is optimized to operate…
By altering the temperature and solvents, we have synthesized hydrated and dehydrated Eu 3+ /Tb 3+ ‐doped REPO 4 (RE=Y, La, and Gd) nanophosphors via a solvo‐thermal technology. X‐ray powder diffraction and scanning electronic microscopy reveal that they have different structures and different morphologies. REPO 4 pre…
A light in the dark: The structure of the mysterious dark conglomerate (DC) phase—probably the first example of chiral segregation in an isotropic fluid smectic—was recently elucidated by an international research team. The new findings (see picture, reprinted with permission and reproduced from Science 2009, 325, 452…
Abstract Transparent conducting Al‐doped and Ga‐doped ZnO thin films (so‐called AZO and GZO, respectively) have been grown on glass substrates by dc magnetron sputtering under identical growth conditions. The thermal stability and the damp heat stability of AZO and GZO thin films deposited at room temperature (RT) as…
This paper presents a new homogenization formula to compute the effective electromagnetic properties for periodic metamaterials. Numerical examples showed that the effective permittivity and permeability of the composites with cubic inclusions, formerly known to have the lowest permittivity, are closer to the Hashin-S…
Coralline red algae assimilate HCO3– to precipitate CaCO3 in their tissues in the form of calcite or aragonite. A characterization of the biomolecular content and the crystalline structure of the biomineral of coralline red algae from the Pacific coast of Mexico was performed by powder X-ray diffraction (XRD), scannin…
Deep subwavelength photolithography with a metallic grating waveguide heterostructure (MGWHS) is presented and numerically demonstrated by a finite-difference time-domain method. This lithography scheme is demonstrated by interference between the diffracted waves of the mask which are enhanced by the surface plasmon p…
Characteristic normal-state charge transport is found in the oxygen-deficient iron-arsenides $Ln{\text{FeAsO}}_{1\ensuremath{-}y}$ ($Ln$: La and Nd) with the highest ${T}_{c}$'s among known Fe-based superconductors. The effect of ``doping'' in this system is mainly on the carrier scattering, quite distinct from that i…
The 62 entries listed in ICSD release 2009/1 under polar space group P 31 m correspond to 31 families of inorganic crystal structures, some with only one member. Coordinate analysis reveals, over a wide confidence range, 11 of these families as ferroelectric candidates. One includes the well known improper ferroelectr…