Materials Literature
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Multicolour colloidal PEI/NaGdF 4 :Ce 3+ ,Ln 3+ (Ln = Tb, Eu, Sm or Dy) nanocrystals were synthesized using a simple one-pot hydrothermal procedure. The nanocrystals consist of well crystallized hexagonal phase and have an elongated spherical shape, with diameters between 25 and 45 nm. Under single-wavelength excitati…
A facile route for synthesizing CuInSe2 nanocrystals was developed using an alkanethiol as ligand and noncoordinating octadecene as solvent. The CuInSe2 nanoparticles and nanoplates were obtained, depending on the reaction temperature and time. When the reaction temperature was set at 180 °C and reaction for an hour,…
In most ferroelectrics, the domain nucleation barrier (U*) is thermally insurmountable; this is called "Landauer's paradox." However, we showed that, in ultrathin films, the large depolarization fields could lower U* to a level comparable to thermal energy (k(B)T), resulting in power-law decay of polarization. We empi…
The electrodeposition of metal (Pd and Pt) nanoparticles on networks of pristine single walled carbon nanotubes (SWNTs) has been investigated using a microelectrochemical cell. A microcapillary containing electrolyte solution and a reference electrode is contacted with a silicon oxide substrate bearing a SWNT network,…
III−VI and I−III−VI semiconductors with anomalous grain boundaries have been actively studied for high efficiency photovoltaic applications. Nanowire morphology can provide a well-defined nanodomain for studying grain boundary and p−n junction physics for improving solar cell efficiency. We report the synthesis of In…
We investigate the electrical properties of composite materials prepared as nano- and sub-micron-scale metal-oxide particles embedded in a commercial resin. The filler particles are barium titanate and calcium copper titanate. The physical and structural characteristics of the constituents and the fabricated composite…
ABSTRACT: Food packaging, although an integral part of the food chain, has a major drawback in that, often, the packaging material interacts with the flavor constituents of the food, causing either a selective or an extensive loss of desirable food flavors or absorption of undesirable off‐flavors from the packaging ma…
Considerable attention has been paid to nanoparticle (NP) research due to their fascinating properties and potential applications in nanotechnology and biotechnology. Asymmetrically functionalizing NPs is of particular interest since it could directly lead to controlled patterning of NPs into complex structures for a…
We report the synthesis and characterization of axial nanorod heterostructures composed of cadmium selenide (CdSe) and cadmium sulfide (CdS). The synthesis employs a solution-liquid-solid (SLS) mechanism with the assistance of bismuth nanocrystals adhered to a substrate (silicon or a III-V semiconductor). Transmission…
Nanosized molecular magnetic materials such as single-molecule magnets and single-chain magnets are recent attractive research targets in the fields of materials chemistry and physics, not only because of their fundamental fascination, but also because of their potential applications as ultimate memory devices or in q…
Humin is the most recalcitrant and least understood fraction of soil organic matter. By definition, humin is that fraction not extracted by traditional aqueous alkaline soil extractants. Here we show that > or = 70% of the traditional humin fraction is solubilized when 0.1 M NaOH + 6 M urea and dimethyl sulfoxide (DMS…
The deliberate structural distortion of a Mn 6 compound via the use of a bulky salicylaldoxime derivative switches the intra-triangular magnetic exchange from antiferromagnetic to ferromagnetic resulting in an S = 12 ground state.
We present an ab initio study of semiconducting carbon nanotubes adsorbed on an unpassivated Si(100) surface. Despite the usual gap underestimation in density functional theory, a dramatic reduction of the semiconducting gap for these hybrid systems as compared with the electronic gaps of both their isolated constitut…
In the past two decades or so, we have learned how to understand crackling noise in a wide variety of systems. We review here the basic ideas and methods we use to understand crackling noise - critical phenomena, universality, the renormalization group, power laws, and universal scaling functions. These methods and to…
Structural and electronic properties of the alpha- and gamma-phases of cerium sesquisulfide, Ce2S3, are examined by first-principles calculations using the GGA+U extension of density functional theory. The strongly correlated f-electrons of Ce are described by a Hubbard-type on-site Coulomb repulsion parameter. A sing…
We use the ab initio local-density approximation (LDA) to study of exchange interactions and Tc of Ga1−xMnxAs grown in digitally doped structures. We analyze the crystallographic dependence of exchange interactions predicted by the LDA in terms of the Mn t2 and e levels, and explain the origin of the antiferromagnetic…
In this work we apply tools developed for the study of fractal properties of time series to the problem of classifying defects in welding joints probed by ultrasonic tecniques. We employ the fractal tools in a preprocessing step, producing curves with a considerably smaller number of points than in the original signal…
We have used complementary neutron and x-ray reflectivity techniques to examine the depth profiles of a series of as-grown and annealed Ga[1-x]Mn[x]As thin films. A magnetization gradient is observed for two as-grown films and originates from a nonuniformity of Mn at interstitial sites, and not from local variations i…
The average and local structures of the (PbTe)1-x(PbS)x system of thermoelectric materials has been studied using the Rietveld and atomic pair distribution function (PDF) methods. Samples with 0:25 < x are macroscopically phase separated. Phase separation was suppressed in a quenched x = 0:5 sample which, nonetheless,…
Pyroelectric and electrocaloric characterization has been determined for 0.75Pb(Mg1∕3Nb2∕3)O3–0.25PbTiO3 relaxor based single crystal and ceramic. Differential scanning calorimetry was used for measuring the electrocaloric response for different electric fields in the vicinity of the Curie temperature. For both cerami…