Materials Literature
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Geometric and electronic structures of a gold−methanethiolate [Au 25 (SCH 3 ) 18 ] + are investigated by using density functional theory. Three types of optimized structures are derived from two different Au 25 core clusters protected by 18 methanethiolates. The most probable optimized structure consists of a Au 7 cor…
Although water is the chief component of living cells, food, and personal care products, the supramolecular components make their viscosity larger than that of water by several orders of magnitude. Using fluorescence correlation spectroscopy (FCS), photon correlation spectroscopy (PCS), NMR, and rheology data, we show…
A simple one-pot solution-phase method was developed to synthesize well-defined copper nanocubes with an edge length in the range of 100 ± 25 nm. Copper nanocubes were produced by using ascorbic acid as a reducing agent and poly(vinylpyrrolidone) (PVP) as a capping agent. X-ray diffraction (XRD), UV–vis spectroscopy (…
The hydrothermal synthesis of the purely inorganic open-framework indium selenide (NH(4))(4)In(12)Se(20) (1) is reported. Compound 1 exhibits a unique three-dimensional open-framework structure. The framework of 1 shows an unusual, for a chalcogenide compound, rigidity arising from the unprecedented connection mode of…
Nature routinely uses cooperative interactions to regulate cellular activity. For years, chemists have designed synthetic systems that aim toward harnessing the reactivity common to natural biological systems. By learning how to control these interactions in situ, one begins to allow for the preparation of man-made bi…
A new magnetic transition in the ruthenocuprate parent compound RuSr2EuCeCu2O10 has been observed below 10 K. It shows up only as a kink in the imaginary part of the ac susceptibility and exhibits a pronounced frequency dependence. At the same time, the real part of the ac susceptibility and the dc magnetization study…
Raman active phonons in the type-I clathrate compounds of ${X}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ $(X=\mathrm{Eu},\mathrm{Sr},\mathrm{Ba})$ have been fully assigned by the combination of polarized Raman scattering and first principles calculations. The dynamical motions of guest ions in the $6d$-site cage have b…
A high coercivity of up to $5.1\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}$ was induced in a large-grained ${\mathrm{CoFe}}_{2}{\mathrm{O}}_{4}$ powder after milling for a short time $(1.5\phantom{\rule{0.3em}{0ex}}\mathrm{h})$. It was found that the initial grain (particle) size played an important role in the microstruc…
The combination of three redox couples Pd2+/Pd0-quinone/hydroquinone-NO2/NO creates an electron-transfer loop, which facilitates one-pot catalytic oxidation of methane selectively to methanol by dioxygen in CF3COOH at a temperature as low as 80 degrees C. This is the first example where an organic cocatalyst significa…
The atomic structure of a carbon nanotube can be defined by the chiral indices, (n,m), that specify its perimeter vector (chiral vector), with which the diameter and helicity are also determined. The fine electron beam available in a modern Transmission Electron Microscope (TEM) offers a unique and powerful probe to r…
We expand our study of the full-Heusler compounds [I. Galanakis et al., Appl. Phys. Lett. 89, 042502 (2006)] to cover also the case of doping and disorder in the case of ${\mathrm{Co}}_{2}\mathrm{Mn}\mathrm{Al}$ and ${\mathrm{Co}}_{2}\mathrm{Mn}\mathrm{Ga}$ half-metallic Heusler alloys. These alloys present a region o…
Based on a quantum dissipation theory of open systems, we present a theoretical study of slow dynamics of magnetization for the ordered state of the molecule-based magnetic complex $[\mathrm{Mn}{(\mathrm{hfac})}_{2}\mathrm{B}\mathrm{N}{\mathrm{O}}_{\mathrm{H}}]$ composed from antiferromagnetically coupled ferrimagneti…
We propose an existence of charge-ordered liquid state in the spinless fermion system on a triangular lattice under strong intersite Coulomb interactions, $V$. The classical ground state in the strong coupling limit is disordered due to geometrical frustration. The introduction of a quantum hopping term lifts the dege…
This letter reports on the observation of optoelectronic switching in addressable molecular crossbar junctions fabricated using polymer stamp-printing method. The active medium in the junction is a molecular self-assembled monolayer softly sandwiched between gold electrodes. The molecular junctions are investigated th…
A new method to directly synthesize single-crystalline CeO 2 nanoparticles has been developed. The advantages of the method are rapid synthesis, at normal atmosphere, 100% productive ratio and low cost, with a great potential for scale-up. X-ray diffraction (XRD) spectra showed unusual peak width versus particle size,…
The metal-insulator transition and unconventional metallic transport in vanadium dioxide $(\mathrm{V}{\mathrm{O}}_{2})$ are investigated with a combination of spectroscopic ellipsometry and reflectance measurements. The data indicate that electronic correlations, not electron-phonon interactions, govern charge dynamic…
Ultrasonically initiated, in situ emulsion polymerization was used to prepare multiwalled carbon nanotube/polyaniline composites (MWNTs/PANI). Transmission electron microscopy (TEM) showed that the nanotubes were coated with a PANI layer, with the thickness of this coating varying with the content of carbon nanotubes…
We show that, in contrast with conventional normal metal-insulator-superconductor (NIS) junctions, the tunneling conductance of a NIS junction in graphene is an oscillatory function of the effective barrier strength of the insulating region, in the limit of a thin barrier. The amplitude of these oscillations is maximu…
The excess entropy, defined as the difference between the entropies of the liquid and the ideal gas under identical density and temperature conditions, is studied as a function of density and temperature for liquid silica and a two-scale ramp potential, both of which are known to possess waterlike liquid state anomali…
We have grown thin films of the Heusler compound ${\mathrm{Co}}_{2}\mathrm{Fe}\mathrm{Si}$ by RF magnetron sputtering. On (100)-oriented MgO substrates we find fully epitaxial (100)-oriented and $L{2}_{1}$ ordered growth. On ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}(11\overline{2}0)$ substrates, the film growth is (110)-orie…