Materials Literature
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We report on the application of Raman scattering as a probe to follow the structural evolution of TiO 2 aerogels. We have traced the evolution of the 142 and 630 cm -1 E g anatase peaks as a function of morphology. The results have been analyzed in terms of the q vector relaxation mechanism which predicts a unique rel…
Monodisperse poly(styrene- b -semifluorinated side chain) block copolymers were synthesized by anionic polymerization of poly(styrene- b -1,2/3,4-isoprene) followed by the corresponding polymer analogous reactions. By controlling the block copolymer composition and the relative lengths of the fluorocarbon and hydrocar…
The instantaneous normal mode (INM) approach to liquid state dynamics is presented. INM is put in historical context, and the underlying physical ideas, including the importance of the potential energy landscape, are explained. It is shown that INM can be the basis of a general starting point for dynamical calculation…
The program DISCUS is a versatile tool for the analysis of diffuse scattering and for defect structure simulations. The model structure can be created from an asymmetric unit of a unit cell or a complete structure can be read from a file. A Fortran77 style interpreter that includes IF statements and various loops comb…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis and Characterization of a Reactive Vinyl-Functionalized MCM-41: Probing the Internal Pore Structure by a Bromination ReactionMyong H. Lim, Christopher F. Blanford, and Andreas SteinView Author Information Department of Chemistry, University of Minnesota 207 P…
Solid-state scientists have many analytical techniques to choose from. But electron energy-loss spectroscopy does some things that no other technique can quite match. Electron energy-loss spectroscopy can, for example, form chemical maps of nanometre-sized regions in solid samples. It can be used to characterize inter…
The metal-insulator transition is mixed-valence manganites of the (${\mathrm{La}}_{0.7}$${\mathrm{Ca}}_{0.3}$)${\mathrm{MnO}}_{3}$ type is ascribed to a modification of the spin-dependent potential ${\mathrm{J}}_{\mathrm{H}}$s\ensuremath{\cdot}S associated with the onset of magnetic order at ${\mathrm{T}}_{\mathrm{C}}…
A simple method is used to prepare highly monodispersed silver nanoparticles in the liquid phase, which starts from an initial synthesis in functionalized AOT reverse micelles. To narrow the particle size distribution from 43% to 12.5% in dispersion, the particles are extracted from the micellar solution. The size-sel…
Exciton energy levels and corresponding optical spectra are calculated in carbon nanotubes (CN) in the conventional screened Hartree-Fock approximation within a k · p scheme. The Coulomb interaction gives rise to several exciton bound states as well as the increase of the energy gap. The exciton energy is shifted to h…
We report the investigation of the steady-state Hall mobility behavior upon extrinsic light excitation in n-type liquid-encapsulated Czochralski GaAs crystals. The carrier concentration of the samples measured in the dark ranged from 108 to 3×1011 cm−3. The Hall mobility demonstrated a pronounced minimum in the concen…
Infrared spectroscopic ellipsometry (IRSE) over the wavelength range from 700 to 3000 cm−1 has been used to study and distinguish the microstructure of polycrystalline hexagonal and cubic boron nitride thin films deposited by magnetron sputtering onto (100) silicon. The IRSE data are sensitive to the thin-film layer s…
Electrochromism was newly realized in a WO3–Pb(Zr0.52Ti0.48)O3 (PZT) system which utilized the piezoelectric property of PZT ceramics for power supply. The electric power produced by Mn-doped PZT ceramics enabled the WO3 film to color blue. High piezoelectricity with a peak voltage of 35 V and peak current of 1.2 mA o…
The miscibility of a diluted polymer blend under steady shear has been investigated in the two-phase region using fluorescence and phase-contrast microscopy. Critical exponents describing the shape of the coexistence curve and the shift of the critical temperature $\ensuremath{\Delta}{T}_{c}(\stackrel{\ifmmode \dot{}\…
We report the first unambiguous identification in a thermotropic liquid crystal of a hexatic smectic- $L$, a phase with molecular tilt direction intermediate between those of the smectic- $I$ and smectic- $F$, using electron diffraction in free-standing films of 5-(4\ensuremath{'}\ensuremath{'}-hexyl,3\ensuremath{'}-f…
X-ray generation enhancement from a laser-produced plasma with a porous Si target is reported. For a porous surface formed on a Si wafer, the self-reflectivity of a femtosecond pulse becomes considerably small. The observed energy penetration depth is 25–30 μm, which is much larger than the skin depth of solid density…
BACKGROUND/AIMS: Dextran magnetite complex (DM) is a colloidal suspension of subdomain magnetite particles ('magnetic fluid'). It has been reported that DM generates a great amount of heat in an AC magnetic field. MATERIAL AND METHODS: In this experimental study on Japanese white rabbits, a new treatment modality for…
Temperature dependent measurements of the 1.54 μm photoluminescence of Er implanted N codoped crystalline Si are made. Upon increasing the temperature from 12 to 150 K, the intensity quenches by more than a factor thousand, while the lifetime quenches from 420 to 3 μs. The quenching processes are described by an impur…
Stability of ordered phases in diblock copolymer melts is studied using a theory of anisotropic fluctuations, which bears a useful similarity with energy band theory in solids. We calculated stability lines of all ordered phases and found the hexagonally perforated lamellar phase to be unstable around the lamellar-cyl…
We report spin-dependent perpendicular transport in the magnetic trilayer junction structure La0.67Sr0.33MnO3/SrTiO3/La0.67Sr0.33MnO3. Large (factor of 5) changes of magnetoresistance induced by a field of ∼200 Oe are observed at 4.2 K. Junction I–V characteristics at low temperatures are consistent with a metal–insul…
A new transparent conducting oxide (TCO), which can be expressed as Ga3−xIn5+xSn2O16; 0.2⩽x⩽1.6, has been identified. The equilibrium phase relationships of this new material with respect to three other TCOs in Ga2O3–In2O3–SnO2 are reported. The optical properties of this phase are slightly superior to Sn-doped indium…