Materials Literature
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We investigate the electromagnetic response of a periodic checker- board consisting of alternating rectangular cells of positive refractive index (ε = +1, μ = +1) and negative refractive index (ε = −1, μ = −1). We show that the system has peculiar imaging properties in that it reproduces images of a source in one cell…
Abstract Nitrous acid deaminative depolymerisation was used to prepare three chitosan oligomer (CO) mixtures from high-molecular weight chitosan. These mixtures of chitosan oligosaccharides were analysed by electrospray ionisation mass spectroscopy, potentiometric titration and gel permeation chromatography. A method…
We report the colossal negative electroresistance (ER) in the p-n heterostructure of La0.67Ca0.33MnO3−δ (LCMO) and Nb-doped SrTiO3. For a vacuum-annealed sample, a maximum ER of 4×104% can be reached by 1 mA current and magnetic field has remarkable influence on the ER of the sample. It is interesting that the magneto…
The performance of coaxially gated, zero-Schottky-barrier, carbon nanotube field-effect transistors is investigated for gate lengths down to 2 nm with source and drain underlaps. Such devices can have nearly ideal subthreshold slopes of ∼63mV∕dec and maximum on∕off current ratios of 2.2×106 assuming 0.0–0.4 volt swing…
Abstract Measurements are reported of the mechanosorptive strain in Pinus radiata specimens stressed either in torsion or in bending. It is demonstrated that, to secure valid data, correction must be made for the moisture-induced distortion at zero load. A series of measurements can be made on a single specimen if two…
Conductivity profiles of nitrogen‐graded zirconia from nitridation of 2 mol% yttria‐doped tetragonal zirconia polycrystals (2Y‐TZP) were determined using microcontact impedance spectroscopy. Local conductivity variations were interpreted in terms of nitrogen concentration and the morphological distribution of the tetr…
Abstract Optical anisotropy of the layer semiconductor GaSe has been studied by photoluminescence (PL) and Fourier Transform Infrared Spectroscopy (FTIR). The PL spectra are dominated by two closely positioned emission bands resulting from the free exciton and the bound exciton connected direct band edge of GaSe. Phot…
BaTi 1−2 y Ga y Nb y O 3 (BTGN) (0≤ y ≤0.35) powders were synthesized at 1300°C by the conventional solid‐state method. Room temperature x‐ray diffraction patterns for y ≤0.025 and 0.05≤ y ≤0.30 can be indexed as the tetragonal ( P 4 mm ) and cubic ( Pm m ) polymorphs of BaTiO 3 , respectively, whereas y =0.35 consist…
The ability to predict and control organic decomposition of a material under arbitrary thermal treatments is one of the main objectives of thermogravimetric studies. The development of this ability provides significant potential to ensure reliability and reproducibility for a given processing method and can be used in…
A structure consisting of an array of wires cladded with a nonmagnetic dielectric and embedded in a ferrimagnetic host has been calculated to have a negative index of refraction. The structure has moderate losses over a bandwidth of a few GHz. The calculation takes into account the skin effect within the wires and is…
Abstract Total photoyield spectroscopy (TPYS) is applied to characterize the surface electronic properties of p‐ and n‐type chemical‐vapour‐deposited (111) homoepitaxial diamond films with hydrogen terminated (H‐terminated) surfaces. All experiments on H‐terminated high quality diamond show the same threshold energy o…
Abstract The surface docking approach of molecular modeling for prediction of crystal morphology in the presence of additives is further developed in this work. It is modified in order to take into account the influence of supersaturation on the crystal habit. With the introduction of the BCF theory and the 2‐D growth…
High-pressure x-ray diffraction and Raman scattering studies on scandium tungstate $[{\mathrm{Sc}}_{2}{(\mathrm{W}{\mathrm{O}}_{4})}_{3}]$ show that it transforms to a monoclinic phase at $\ensuremath{\sim}0.6\ifmmode\pm\else\textpm\fi{}0.3\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The high-pressure phase has $P{2}_{1}…
Abstract Ultraviolet absorbers, such as those from the hydroxyphenylbenzotriazole and hydroxybenzophenone classes of compounds, are typically added to flexible PVC roofing membranes in order to protect the membranes during long‐term exposure to sunlight. In this article a radically new UV stabilizer, one that is not j…
Abstract The reactive ion etching (RIE) procedures were applied for mechanically polished {111} diamond substrates surfaces using oxygen and hydrogen gas sources to improve the crystalline quality of chemical vapor deposited (CVD) n‐type diamond layers. The growth of phosphorus‐doped films was performed on RIE treated…
The molecular structures of ${\mathrm{Si}}_{29}{\mathrm{H}}_{24}$, ${\mathrm{Si}}_{29}{\mathrm{H}}_{36}$, and ${\mathrm{Si}}_{35}{\mathrm{H}}_{36}$ clusters in the ground state as well as in the lowest singlet and triplet excited states have been studied at the density-functional theory level using the first-order lin…
Abstract A basic study was carried out to understand effect of Cetyl Pyridinium Cloride (CPC) on calcium sulfate dihydrate (gypsum) crystallization. Induction time was measured under different supersaturation ratios ranging from 1.222 to 1.979. This is the time elapsed between the achievement of supersaturation and th…
Abstract Potassium Chloride (KCl) and Ethylene diamine tetraacetie acid (EDTA) as new additives were added into the KDP solutions in a small amount (5M% and 0.01M% respectively). The solubility curve and metastable zone width of KDP solution with 5M%KCl was determined and we explained the mechanism of rapid growth of…
Although the hard magnetic SmCo5 phase has very attractive and well-known intrinsic magnetic properties, it has not been grown as an epitaxial thin film, so far. This letter reports the epitaxial growth of SmCo5 films by pulsed-laser deposition on Cr(100) buffered MgO(100) single-crystal substrates. The phase purity,…
A facile chemical route to prepare a well‐defined Ni powder on a mass‐production scale without external heating was suggested. A highly concentrated Ni complex was formed between NiCl 2 and N 2 H 4 solution, and subsequent addition of NaOH solution triggered serial reactions from the Ni complex decomposition via Ni(OH…