Materials Literature
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We present Maxwell equations with source terms for the electromagnetic field interacting with a moving electron in a spin-orbit coupled semiconductor heterostructure. We start with the eight--band ${\bm k}{\bm p}$ model and derive the electric and magnetic polarization vectors using the Gordon--like decomposition meth…
Synchrotron infrared measurements were conducted over the range 100 to 8000 cm-1 on a self-doped LaxMnO3-d (x~~0.8) film. From these measurements we determined the conductivity, the effective number of free carriers, and the specific phonon modes as a function of frequency. While the metal-insulator transition tempera…
A new class of boron-dipyrromethene (BDP or BODIPY) dyes was obtained by phenanthrene fusion to the beta-pyrrole positions, absorbing in the wavelength range of important laser sources. Despite a 'propeller-like' distorted structure in the crystalline state, the chromophore absorbs (log epsilon > or = 5) and fluoresce…
High-pressure resistivity and x-ray diffraction have been measured on La0.85MnO3-d. At low pressures the metal-insulator transition temperature (TMI) increases linearly with pressure up to a critical pressure, P* ~ 3.4 GPa, which is followed by reduction of TMI with increasing pressure. Analysis of the bond distances…
We have performed X-ray magnetic circular dichroism (XMCD) and valence-band photoemission studies of the diluted ferromagnetic semiconductor Zn 1- x Cr x Te. XMCD signals due to ferromagnetism and paramagnetism and/or superparamagnetism were observed at the Cr 2p absorption edge. Comparison with atomic multiplet calcu…
We study the charge density distribution, the electric field profile, and the resistance of an electrostatically created lateral p-n junction in graphene. We show that the electric field at the interface of the electron and hole regions is strongly enhanced due to limited screening capacity of Dirac quasiparticles. Ac…
Wool and silk were dissolved and used for the preparation of blended films. Two systems are proposed: (1) blend films of silk fibroin and keratin aqueous solutions and (2) silk fibroin and keratin dissolved in formic acid. The FTIR spectra of pure films cast from aqueous solutions indicated that the keratin secondary…
Nanoshell arrays have recently been found to possess ideal properties as a substrate for combining surface enhanced raman scattering (SERS) and surface enhanced infrared absorption (SEIRA) spectroscopies, with large field enhancements at the same spatial locations on the structure. For small interparticle distances, t…
The dimensionless thermoelectric figure of merit (ZT) in bismuth antimony telluride (BiSbTe) bulk alloys has remained around 1 for more than 50 years. We show that a peak ZT of 1.4 at 100 degrees C can be achieved in a p-type nanocrystalline BiSbTe bulk alloy. These nanocrystalline bulk materials were made by hot pres…
The design andsynthesis of basic porphyrin building blocks for the con-struction of highly ordered systems often require incorpo-ration of different peripheral substituents. The synthesis ofporphyrins bearing specific patterns of functionality is stillchallenging task in spite of the ample presence of reportedprocedur…
The spin Hamiltonian (SH) parameters g factors g ‖ , g ⊥ and the hyperfine structure constants A ‖ and A ⊥ for the tetragonal Cu 2+ centers (i.e., [ CuX 4 ( H 2 O ) 2 ] clusters) in NH 4 X ( X = Cl, Br, I ) are theoretically investigated by means of the diagonalization procedure of complete (10×10) energy matrix (DPCE…
Lead(II) 4,4,4-trifluoro-1-phenyl-1,3-butandionate (TFPB−) complexes with 1,10-phenanthroline (phen) and 2,2′-bipyridine (2,2′-bipy), [Pb(L)(TFPB)2], have been synthesized and characterized by elemental analysis, IR-, 1H NMR spectroscopy and studied by X-ray crystallography. The self-assembly of [Pb(L)(TFPB)2] complex…
Current transport in carbon nanotube field effect transistors (CNT-FETs) has been modeled from charge distributions and the potential inside the carbon nanotube. Analytical equations describing I-V characteristics of the CNT-FETs have been obtained from the combination of diffusion and drift mechanisms in the channel…
We report the synthesis and evaluation of thermal behavior of two new mesogenic homologous series of liquid crystalline compound containg 1,2,4-triazole and isonicotinic acid ring at the terminus of the molecule viz. 4-[(4H-1,2,4-triazol-4-ylimino) methyl] phenyl 4-alkoxybenzoate and 4-(2-isonicotinoylcarbonohydrazono…
Abstract The objective of this work is to study the optical and electrical properties of tantalum nitride and tantalum barrier thin films used against copper diffusion in Si in integrated circuits using spectroscopic ellipsometry in the VUV and UV–visible range. Single layers of tantalum nitride and bilayer films of T…
In the nuclear industry, large volumes of liquid wastes with a low radioactivity have to be treated. The method which is commonly applied to remove contaminants consists of the use of an insoluble finely divided solid material formed in situ by precipitation in the waste stream. In this study, a new mathematical appro…
Abstract The dielectric constant (ε′), dielectric loss index (ε″), direct‐current conductivity, and current–voltage ( I – V ) characteristics of pure poly(vinyl chloride) (PVC) and blends of PVC and bisphenol A/Egyptian corncobs (BCC) were investigated at different temperatures. The relaxation processes for PVC and it…
Abstract KDP crystals were rapidly grown from solution doped with different Ba 2+ concentrations. The effects of Ba 2+ on the growth rate, morphology and quality of KDP crystals were discussed. Significant changes in shapes and volume of the grown crystals have been observed. During the growth process, defect region e…
The single mutants (F165A, E192A, F196A, S392A, T393A) at and near the main hinge (beta-strand L) of human 3-phosphoglycerate kinase (hPGK) exhibit variously reduced enzyme activity, indicating the cumulative effects of these residues in regulating domain movements. The residues F165 and E192 are also essential in mai…
Semiconductor, Poly(vinyl pyrrolidone), Chemical reduction, SeleniumElemental selenium (Se) is a narrow band gap (~1.7 eV)semiconductor which has been extensively used in solarcells, xerography and rectifiers. It is also a photoconductorwith a relatively low melting point (~217 °C), high refrac-tive index and high rea…