Materials Literature
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The out-of-plane current-voltage (I-V) characteristics of Bi2212 are studied in experimental environments of different heat transfer efficiency, allowing practical separation of intrinsic and extrinsic phenomena. {\it Intrinsic} (heating-free) response is Ohmic in the normal state of Bi2212, while its resistance, R=V/…
Negatively and positively charged excitons are identified in the spatially-resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the "binding energy" of a charged exciton is caused, for a signific…
It is found that both of the band-edge and defect emission from aligned ZnO nanorods are strongly polarized, and the intensities vary with the polarization angle by the relation of a square cosine function. The intensity of the UV emission has its maximum along the c axis of a ZnO crystal. However, the intensity of th…
We report unambiguous evidence for superconductivity in a heavily boron-doped diamond thin film grown by microwave plasma-assisted chemical vapor deposition (MPCVD). An advantage of the MPCVD-deposited diamond is that it can contain boron at high concentration, especially in (111)-oriented films. Superconducting trans…
The growth of Cu2O crystals that are electrochemically deposited as micrometer-size crystals with systematically varying fractions of {100} and {111} faces is reported (the Figure depicts cubic crystals). The methodical and homogeneous shape evolution is achieved by tuning the degree of preferential adsorption of sodi…
Abstract Recent advances in the exploitation of localized surface plasmons (charge density oscillations confined to metallic nanoparticles and nanostructures) in nanoscale optics and photonics, as well as in the construction of sensors and biosensors, are reviewed here. In particular, subsequent to brief surveys of th…
The scattering length density profile for a thin film structure can be determined uniquely if both modulus and phase of the reflection coefficient is known. Here, we describe a method for recovering the phase information which utilize a magnetic substrate and based on polarization analysis of the reflected beam. The m…
We present a theoretical study of diluted magnetic semiconductors that treats the local sp-d exchange interaction J between the itinerant carriers and the Mn d electrons within a realistic band structure and goes beyond previous mean-field approaches. In case of (Ga,Mn)As, we find that strong exchange potentials tight…
We present a systematic 57 Fe Mössbauer effect study in the temperature range between 5.3 and 298.2 K and in an external magnetic field of 9.0 T of a high-quality stable decagonal quasicrystal Al 70 Co 15 Ni 14.9 Fe 0.1 . The iron atoms are shown to be located in two distinct classes of sites. The values of the princi…
Abstract The reflux of mononuclear ruthenium precursor [RuII(acac)2(CH3CN)2] (acac = acetylacetonate) in 2-methyl-2-propanol formed the novel diamagnetic β-diketonato ruthenium tetranuclear complex [Ru(μ-acac)2(μ3-O)2Ru3(acac)6] (1), in which was contained the deltoid core, [Ru4(μ3-O)2]8+, consisting of four ruthenium…
Europium-doped yttrium silicate nanoparticles were grown inside a porous silicon oxide matrix by chemical impregnation of porous silicon layers, followed by heat treatments. The average size of the nanoparticles is 50 nm and they are dispersed almost uniformly within the whole porous layer. Local composition measureme…
Si nanocrystals were formed by the implantation of Si+ into a SiO2 film, deposited on (100) Si, followed by high-temperature annealing. Transmission electron microscopy?(TEM) was used to examine the effect of implantation dose on the microstructure of the Si nanocrystals?(Si?nc) in the SiO2 film. The size and spatial…
Results of the low frequency dielectric constant (ε), dielectric loss and x-ray powder diffraction (XRD) measurements on orthorhombic Al 2 (WO 4 ) 3 under pressure are reported. The dielectric constant and the dielectric loss both show a sharp peak at about 0.5 GPa, indicating a ferroelastic phase transformation. This…
We study, in detail, the influence of molecular interactions on the Frank elastic constants of uniaxial nematic liquid crystals composed of molecules of cylindrical symmetry. This work is based on a weighted density functional formalism developed by us in a previous paper (Singh et al 1992 Phys. Rev. A 30 583). A brie…
Abstract The growth process of poly(isobutyl methacrylate) (PiBMA) particle prepared in soap-free polymerization using V-50 as an initiator was observed by atomic force microscopy (AFM) to clarify the growth mechanism. As a result, it was found that PiBMA particles were capable of growing by the adhesion of smaller pa…
Two new phosphonium chloroantimonate(III) and chlorobismuthate(III) crystals ([(CH3)4P]3[Sb2Cl9] (PCA) and [(CH3)4P]3[Bi2Cl9] (PCB)) have been synthesized and their structure determined by means of single-crystal x-ray diffraction. The structure of the title compounds contains discrete [M2Cl9]3− anions in general posi…
Neutron diffraction, transversal field μSR and magnetization studies of La 1− x Sr x CoO 3 with x = 0.15 and 0.3 has been performed. Long-range ferromagnetic ordering has been found only in the x = 0.3 sample. Magnetization measurements indicate the inhomogeneous magnetic state of this system. Magnetization data confi…
Studies of dielectric permittivity as a function of the temperature and frequency on Li–Na niobate ceramics in the x = 0–5% Li compositional range have been performed. The results obtained for compositions with have revealed small wide anomalies below the temperature of the main peak corresponding to a ferroelectric (…
Near-infrared (NIR) spectroscopy is ill-suited to microanalysis because of its low absorptivity. We have developed a highly sensitive detection method for NIR spectroscopy based on absorption-sensitive surface plasmon resonance (SPR). The newly named SPR-NIR spectroscopy, which may open the way for NIR spectroscopy in…
A series of dendronized poly( p -phenyleneethynylene)s were synthesized by the Pd-catalyzed coupling of a tetraphenylbenzene-substituted aromatic diiodide to 2,5-didodecyl-1,4-diethynylbenzene to form PPEs in excellent yield and high degree of polymerization. The tetraphenylbenzene-substituted monomer was obtained by…