Galo J. A. A. Soler‐Illia、Eduardo L. Crepaldi、David Grosso 等 5 位作者2002-09-19Chemical Communications
Large pore (a = 150-200 A) wormlike and highly oriented cubic (IM3m space group) and 2D-hexagonal (P6m) mesostructured xerogels have been reproducibly synthesised by Evaporation-Induced Self Assembly (EISA). Mesostructure control was attained by changing the template (nonionic block copolymer) and water (h = [H2O]/[Si…
Zeolite Catalysis and SynthesisMesoporous Materials and CatalysisPolyoxometalates: Synthesis and Applications
Masahiko Hiratani、S. Kimura、Tomoyuki Hamada 等 5 位作者2002-09-19Applied Physics Letters
A tantalum–pentoxide dielectric with an enhanced permittivity of over 50 was found to be crystallized in a hexagonal symmetry with a=0.628 nm and c=0.389 nm. The incommensurate epitaxy of tantalum pentoxide on hcp-ruthenium metal stabilizes the hexagonal phase with √3-time periodicity in plane, as compared with that o…
Ferroelectric and Piezoelectric MaterialsSemiconductor materials and devicesMicrowave Dielectric Ceramics Synthesis
B. Averboukh、R. Huber、Kok‐Wai Cheah 等 7 位作者2002-09-19Journal of Applied Physics
Photoluminescence and electroluminescence from a Si/SiO2 superlattice have been measured. They show similar characteristics and exhibit an inhomogeneously broadened photoluminescence band peaked at 2.06 eV. The excitation spectrum indicates that excitations occur in the Si layers. The insensitivity of the luminescence…
Semiconductor materials and devicesThin-Film Transistor TechnologiesSilicon Nanostructures and Photoluminescence
John M. Lupton2002-09-19Applied Physics Letters
A highly sensitive molecular thermometer based on platinum octaethyl porphyrin, which can be employed in a range of environments, is presented. The thermal activation of the emission spectrum results in a change in emission intensity by an order of magnitude over a temperature range of 45 K about room temperature. The…
Organic Light-Emitting Diodes ResearchMolecular Junctions and NanostructuresLuminescence and Fluorescent Materials
Fengxia Hu、Xiaolong Qian、Jirong Sun 等 7 位作者2002-09-19Journal of Applied Physics
Magnetic entropy change ΔS of compounds La(Fe1−xCox)11.2Si1.8 with the cubic NaZn13-type structure was investigated around their Curie temperature TC. It is found that the phase transition is completely reversible, indicating a nature of second order phase transition. The maximum value of |ΔS|∼13.0 J/kg K under a fiel…
Magnetic and transport properties of perovskites and related materialsRare-earth and actinide compoundsAdvanced Condensed Matter Physics
Zhiwei Li、Linfeng Chen、C. K. Ong2002-09-19Journal of Applied Physics
Static and high-frequency magnetic properties have been studied for BaFe12−2xCoxZrxO19 with x=0–1.2. The x-ray diffraction and M–H curves of aligned samples show that Co–Zr substitution can modify the anisotropy of BaFe12−2xCoxZrxO19. BaFe12−2xCoxZrxO19 with x⩽0.6 has an easy c-axis anisotropy and the anisotropy field…
Magnetic Properties and Synthesis of FerritesElectromagnetic wave absorption materialsMagneto-Optical Properties and Applications
Enrique de Miguel、Carlos Vega2002-09-19The Journal of Chemical Physics
The phase diagram of the Gay–Berne model with anisotropy parameters κ=3, κ′=5 has been evaluated by means of computer simulations. For a number of temperatures, NPT simulations were performed for the solid phase leading to the determination of the free energy of the solid at a reference density. Using the equation of…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesNonlinear Dynamics and Pattern Formation
Amarendra K. Singh、T. C. Goel、R. G. Mendiratta 等 5 位作者2002-09-19Journal of Applied Physics
Mn x Ni 0.5−x Zn 0.5 Fe 2 O 4 ferrites with x=0.05, 0.1, 0.2, 0.3, and 0.4, have been synthesized by the citrate precursor method and investigated for their magnetic properties. The initial relative permeability is observed to increase with increase in manganese concentration up to x=0.2 followed by a decrease, the ma…
Multiferroics and related materialsMagnetic Properties and Synthesis of FerritesMagneto-Optical Properties and Applications
T. Makino、Kentaro Tamura、C. H. Chia 等 7 位作者2002-09-19Applied Physics Letters
We studied photoluminescence (PL) properties of eighteen samples of wurtzite ZnO/MgxZn1−xO multiple quantum wells (x=0.12 and 0.27) with various well widths (Lw) of 0.7–4.65 nm. Radiative recombination of the electron–hole pairs that are spatially separated due to the quantum-confined Stark (QCS) and Franz–Keldish (QC…
ZnO doping and propertiesGa2O3 and related materialsElectronic and Structural Properties of Oxides
Brian C. Daly、H. J. Maris、A. V. Nurmikko 等 5 位作者2002-09-19Journal of Applied Physics
We report on measurements of the thermal conductivity of epitaxially grown nitride thin films. These semiconductor materials are of considerable technological importance for applications such as blue-light emitters and high-power, high frequency electronic devices. Measurements were made in the temperature range of 15…
GaN-based semiconductor devices and materialsThermal properties of materialsThermography and Photoacoustic Techniques
Mingjun Jia、Werner R. Thiel2002-09-19Chemical Communications
A hybrid heterogeneous catalyst system, which has been synthesized by covalently anchoring oxodiperoxo molybdenum chelate complexes onto the surface of mesoporous MCM-41, is highly active and truly heterogeneous for the liquid-phase epoxidation of cyclooctene with tBuOOH as the oxygen source.
Mesoporous Materials and CatalysisPolyoxometalates: Synthesis and ApplicationsOxidative Organic Chemistry Reactions
Г. Е. Заиков、С. М. Ломакин2002-09-19Journal of Applied Polymer Science
Abstract The use of polymer flame retardants has an important role in saving lives. The main flame retardant systems for polymers currently in use are based on halogenated, phosphorous, nitrogen, and inorganic compounds. All of these flame retardant systems basically inhibit or even suppress the combustion process by…
Polymer Nanocomposites and PropertiesFlame retardant materials and propertiesPolymer Science and PVC
Éric Devaux、Serge Bourbigot、Ahmida El Achari2002-09-19Journal of Applied Polymer Science
Abstract Polyamide‐6 (PA‐6)/clay (modified montmorillonite) hybrid was synthesized by melt blending at high shear stress. 27 Al‐NMR of solid state shows that the clay is not modified after melt blending. Using wide‐line 1 H‐NMR and TEM, it is demonstrated that the nanocomposite exhibits mainly an exfoliated structure.…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesPolymer Nanocomposite Synthesis and Irradiation
Madhuri Mandal、Sujit Kumar Ghosh、Subrata Kundu 等 5 位作者2002-09-19Langmuir
Formation of stable gold nanoparticles of different size and shape has been reported via UV photoactivation of HAuCl 4 in variable concentrations of TX-100. It has been shown that smaller particles of gold preferentially dissolved by cyanide at a faster rate in air in comparison to that for the larger particles becaus…
Gold and Silver Nanoparticles Synthesis and Applicationsnanoparticles nucleation surface interactionsLaser-Ablation Synthesis of Nanoparticles
Todd Brintlinger、Yung‐Fu Chen、T. Dürkop 等 7 位作者2002-09-19Applied Physics Letters
We demonstrate the use of field-emission scanning electron microscopy for rapid imaging of small-diameter carbon nanotubes on insulating SiO2 substrates. The image contrast stems from local potential differences between the nanotube and substrate and is insensitive to surface roughness and defects. This technique may…
Carbon Nanotubes in CompositesForce Microscopy Techniques and ApplicationsMechanical and Optical Resonators
Erjuan Hao、George C. Schatz、Robert C. Johnson 等 4 位作者2002-09-19The Journal of Chemical Physics
We experimentally demonstrate for the first time the existence of distinguishable contributions to hyper-Rayleigh scattering (HRS) intensities from Ag nanoparticles arising from electric–dipole and electric–quadrupole plasmon resonances at the emitted wavelength. We show that these results can be successfully modeled…
Gold and Silver Nanoparticles Synthesis and ApplicationsPlasmonic and Surface Plasmon ResearchProtein Interaction Studies and Fluorescence Analysis
M. Acet、E. Duman、E. F. Wassermann 等 5 位作者2002-09-19Journal of Applied Physics
The structural and magnetic properties of stoichiometric Ni2MnAl are studied to clarify the conditions for ferromagnetic and antiferromagnetic ordering claimed to occur in this compound. X-ray and magnetization measurements show that although a single phase B2 structure can be stabilized at room temperature, a single…
Shape Memory Alloy TransformationsIntermetallics and Advanced Alloy PropertiesHeusler alloys: electronic and magnetic properties
Shaoguang Yang、A. B. Pakhomov、S.T. Hung 等 4 位作者2002-09-19Applied Physics Letters
Synthesis and characterization of magnetic semiconductors Al1−xCrxN, in which the atomic fraction of chromium x is up to 0.357, are reported. The films, grown by reactive co-sputtering on silicon, glass, and kapton substrates, have a crystal structure of aluminum nitride. Magnetic and transport properties were studied…
ZnO doping and propertiesMetal and Thin Film MechanicsAcoustic Wave Resonator Technologies
Gemma Ibarz、Lars Dähne、Edwin Donath 等 4 位作者2002-09-19Chemistry of Materials
The influence of thermal treatment on the permeability of polyelectrolyte multilayer capsules is studied via confocal fluorescence microscopy of individual microcapsules. For the specific most frequently used example, capsules made of poly(styrenesulfonic acid) and poly(allylamine hydrochloride), the penetration of fl…
Advanced Polymer Synthesis and CharacterizationPolymer Surface Interaction StudiesDendrimers and Hyperbranched Polymers
Michael Malkoch、Eva Malmström、Anders Hult2002-09-19Macromolecules
A divergent approach to synthesize dendritic aliphatic polyester structures based on 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) is described. The key building block is the anhydride of isopropylidene-2,2-bis(methoxy)propionic acid which is synthesized in high yields through self-dehydration, utilizing N,N ‘ -dicyc…
Chemical Synthesis and AnalysisDendrimers and Hyperbranched PolymersSynthesis and properties of polymers