Materials Literature
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Band discontinuities and band bending at the epitaxial SrTiO3∕GaAs(001) interface were investigated using x-ray and ultraviolet photoelectron spectroscopy. Results showed that the epitaxial SrTiO3∕GaAs(001) formed a type II heterojunction with conduction and valence band offsets being 0.6 and 2.5 eV, respectively, for…
A trisilanol polyhedral oligomeric silsesquioxane (POSS), trisilanolcyclohexyl-POSS (TCyP), has recently been reported to undergo a series of phase transitions from traditional Langmuir monolayers to unique rodlike hydrophobic aggregates in multilayer films that are different from "collapsed" morphologies seen in othe…
A mechanochemical intercalation approach which applies a simple mechanical milling to induce intercalation reaction was applied to introduce controlled amount of tetraethoxylsilane (TEOS) into surfactant-preexpanded graphite oxide, and the relationships between the intercalation structure, the porosities of the calcin…
Using a full potential linearized muffin-tin approach and the spin polarized density functional method, we studied the magnetism and the electronic structure for transition metal pnictides in the zinc blende (ZB) and the wurtzite (WZ) structures under volume expansion and compression. It was found that for many compou…
Closing individual, thin, multiwalled carbon nanotubes is performed in situ in a transmission electron microscope (see Figure). The closure of the initially open end of the nanotube results from the presence of a strong electric field and the accompanied electron emission. The closed-cap nanotubes exhibit high current…
The infrared low-temperature Ar-matrix spectra of 5-halouracils and unsubstituted uracil were measured and interpreted in terms of the spectra calculated at the DFT/B3PW91/6-311G level followed by a potential energy distribution (PED) analysis. For the PED analysis, the sets of halouracil mode definitions were constru…
Epitaxial layers of Ga 1− x Mn x N with concentrations of up to x = 0.015 have been grown on c-sapphire substrates by metalorganic chemical vapour deposition. No ferromagnetic second phases were detected via high-resolution x-ray diffraction. Crystalline quality and surface structure were measured by x-ray diffraction…
The crystal and the magnetic structures as well as magnetostriction of the Laves-phase compound $\mathrm{Nd}{\mathrm{Co}}_{2}$ are investigated by means of temperature-dependent high-resolution neutron-powder diffraction. The compound crystallizes in the cubic Laves phase $C15$ structure at high temperature, undergoes…
Cross sections at low energies for vibrationally elastic and inelastic scattering, as well as electron attachment to $\mathrm{S}{\mathrm{F}}_{6}$, have been calculated using a multichannel effective range theory (ERT) with complex boundary conditions. The most active vibrational modes, the totally symmetric mode ${\en…
We investigate the early stages of mass convection in a colloidal suspension at high solutal Rayleigh number ${\stackrel{^}{\mathrm{R}\mathrm{a}}}_{s}$. From the time evolution of shadowgraph images and by assuming a diffusive growth of the boundary layers we obtain an indirect measurement of the concentration boundar…
We report the first synthesis of titanium nitride (TiN) nanoparticles inside the nanoscale channels of mesoporous silica SBA-15. The TiN precursor, Ti(NMe(2))(4) in toluene, was incorporated into the methyl group-modified channels of the SBA-15 powder. The functionalization of pore surfaces with methyl groups generate…
Development of simple and reliable protocols for the synthesis of organically soluble catalytically active metal nanoparticles is an important aspect of research in nanomaterials. We demonstrate herein the formation of Pd nanoparticles by reduction of aqueous Pd(NO(3))(2) by photoexcited Keggin ions (phosphotungstate…
The complexation of Dawson-type polyoxometalates of [α-P 2 W 18 O 62 ] 6 -, [α 2 -P 2 W 17 V 1 O 62 ] 7 -, and [α-P 2 W 15 V 3 O 62 ] 9 - with the macrocation ([Cr 3 O(OOCH) 6 (H 2 O) 3 ] + ) forms ionic crystals of (NH 4 ) 4 [Cr 3 O(OOCH) 6 (H 2 O) 3 ] 2 [α-P 2 W 18 O 62 ]·15H 2 O ( 1a ), (NH 4 ) 5 [Cr 3 O(OOCH) 6 (H…
A new synthesis method for preparation of thin films and powders consisting of zeolite beta nanocrystals embedded in ordered mesoporous silica matrix is described. The final structures possessing bimodal porosity, i.e., high degree of mesophase order and spatially defined microporous zeolite nanocrystals are obtained…
Undoped BaTiO3 ceramic samples with an average grain size of ∼35nm were prepared and the electrical properties investigated. The defect structure is dominated by acceptor impurities; therefore, the conductivity of nanocrystalline BaTiO3 is of p-type. Comparing with microcrystalline BaTiO3, the conductivity of nanocrys…
Hollow and filled Ni microspheres are fabricated by a photocatalytic approach using polyelectrolyte capsules as templates. Because of the different crystallization conditions existing in the capsule shell and the interior volume, Ni nanorods are formed inside the capsule, whereas only small, spherical Ni nanoparticles…
We report on the interaction of light with a particular class of media---wet gels, which in contrast to sols of nanoparticles possess a macroscopic bulk structure, and which differ from conventional solids by the existence of the internal liquid-solid interface. We show, taking an absorption cross section of trapped e…
This work describes the use of atomic force microscopy (AFM) to measure the size of dendrimer-stabilized Pt nanoparticles (Pt DNs) deposited from aqueous solutions onto mica surfaces. Despite considerable previous work in this area, we do not fully understand the mechanisms by which PAMAM dendrimers template the forma…
Layered organic superconductors are on the verge of the Mott insulator. We use the Gutzwiller variational method to study a two-dimensional Hubbard model including a spin exchange coupling term as a minimal model for the compounds. The ground state is found to be a Gossamer superconductor at small on-site Coulomb repu…
Porous nanostructured mixed-conducting materials with dual-scale porosities are fabricated using foam-like templates. The porous structures, as shown in the Figure, contain large pores (0.8–1.5 μm) for rapid gas transport and small pores (≈ 2.5 and 35 nm) for fast electrochemical reactions that require large surface a…