Materials Literature
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A monoclinic phase was recently discovered near the morphotropic phase boundary in several high-performance piezoelectric perovskite solid solutions, but its properties have not been reported. In this paper the dielectric, piezoelectric, and ferroelectric properties of the monoclinic Pm phase in the $(1\ensuremath{-}x…
It has been shown in recent experiments that electronic transport through a gold monatomic nanowire is dissipative above a threshold voltage due to excitation of phonons via the electron-phonon interaction. We address that data by computing, via density functional theory, the zone boundary longitudinal phonon frequenc…
We represent the results of quantum chemical calculations of boron nitride nanotubes intercalated by alkali and alkali-earth metall atoms and its ions. It was obtained that unpair spins were localized on seperated metal atoms. So we propose to construct the two-qubit cells on the basis of infilled boron nitride nanotu…
A prototype of magnetoresistive random access memory (MRAM) based on magnetic tunnel junctions (MTJ) was fabricated with crossed-anisotropy of magnetic layers on either side of the tunnelling barrier layer. It is demonstrated that the introduction of crossed-anisotropy results in smaller switching fields and better sw…
Scanning Probe Microscopy is used to study and quantify the nanoscale electric phenomena in the two classes of oxide systems, namely transport at electroactive grain boundaries and surface behavior of ferroelectric materials. Scanning Impedance Microscopy is developed to study the capacitance and local C-V characteris…
We develop a theory to study the characteristics of dipolar / strain fluctuations in perovskite relaxors. In addition to the soft TO and TA phonons, we take into account another freedom of motion associated with the random hopping of $\mathrm{Pb^{2+}}$ ions between the off-center sites around the high symmetry corner…
Alumina-borate/PVA composite fibres were prepared using sol–gel processing and an electrospinning technique. After calcination of the thin fibres, ultra-fine fibres of alumina-borate oxide with a diameter of about 550 nm could be prepared. The fibres were characterized by SEM, XRD and FT-IR. The results showed that th…
A series of systematic DFT calculations were conducted on Keggin [SiW(9)M(3)O(40)](n-), M = Mo, V, and Nb; and Wells-Dawson anions [P(2)M(18)O(62)],(6-) M = W and Mo; [P(2)M(15)M(3)'O(62)](m-), M = W and Mo, M' = W, Mo, and V to analyze the redox properties and the basicity of the external oxygen sites in polyoxometal…
We use conventional and multispeckle dynamic light scattering to investigate the dynamics of a wide variety of jammed soft materials, including colloidal gels, concentrated emulsions, and concentrated surfactant phases. For all systems, the dynamic structure factor f(q,t) exhibits a two-step decay. The initial decay i…
Can gadolinium III [Gd(III)] complexes be considered good candidates for magnetic resonance (MR)-molecular imaging studies? In this review article, we examine the principal issues that are the basis of successful use of Gd-based protocols in molecular imaging applications. High relaxivity is the primary requisite. The…
A series of novel meso-(8-substituted naphth-1-yl)porphyrins has been synthesized creating derivatives with a tight recognition environment above the porphyrin plane. The selective synthesis of single atropisomers is discussed. Condensation of bisnaphthaldehyde 12 with phenyldipyrromethane unexpectedly led to selectiv…
In this paper a high efficiency and flexible hybrid system representing a new total energy concept for the distributed power market is presented. The hybrid system is composed of a very small size (5 kW) micro gas turbine (named personal turbine—PT) presented in a companion paper by the authors coupled to a small size…
A survey of the October 2001 release of the Cambridge Structural Database [Cambridge Structural Database (1992). Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, England] has uncovered approximately 675 separate apparently reliable entries under space groups P3, P3(1), P3(2) and R3; in approximately 1…
We consider the problem of nonlinear convection in horizontal mushy layers during the solidification of binary alloys. We analyse the oscillatory modes of convection in the form of two- and three-dimensional travelling and standing waves. Under a near-eutectic approximation and the limit of large far-field temperature…
Abstract Polyaniline (PAN), poly( o ‐bromoaniline) (POBA), and poly(aniline‐ co‐o ‐bromoaniline) (PABA) were synthesized by oxidative coupling. These polymers are protonated by 10–20% methane sulfonic acid (MSA) and 1 M HCl. The new polymer bases have greater solubility than that of PAN in common polar organic solvent…
Abstract The synthesis of chitosan methylcarbamate (ChMC) and ethylcarbamate (ChEC) is described by using a new methodology. Polymers with substitution degrees up to 63% for ChEC and 68.5% for ChMC were obtained. Derivatives with lower substitutions were acid soluble but those with higher ones were completely insolubl…
Computer animation of center of mass coordinates obtained from 800 ps molecular dynamics simulations of Cs-smectite hydrates (1/3 and 2/3 water monolayers) provided information concerning the structure and dynamics of the interlayer region that could not be obtained through traditional simulation analysis methods. Cs…
Antimony telluride doped with small concentrations of vanadium was recently identified as a diluted magnetic semiconductor. We present a study of the heat transport in single crystals of ${\mathrm{Sb}}_{2\ensuremath{-}x}{\mathrm{V}}_{x}{\mathrm{Te}}_{3}$ with $x=0,$ 0.01, 0.02, and 0.03. Thermopower and thermal conduc…
[reaction: see text] A dendrimer with rotaxane-like characteristics has been assembled under thermodynamic control from complementary wedge-shaped precursors by slippage in CH(2)Cl(2). The driving force for the self-assembly process is the molecular recognition that exists as a result of [N(+)-H.O] and [C-H.O] hydroge…
This paper reports a simple method for the multilayer immobilization of conjugated polymers, gold nanoparticles on solid supports. Poly(phenyenevinylene) functionalized with aldehyde and aminooxy groups was chemoselectively immobilized onto both glass and gold substrates via layer-by-layer deposition. The physical pro…