Transport and magnetic properties of LT annealed Ga1-xMnxAs
We present the results of low temperature (LT) annealing studies of Ga1-xMnxAs epilayers grown by low temperature molecular beam epitaxy in a wide range of Mn concentrations (0.01
Materials Literature
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Fabrication of Honeycomb Film of an Amphiphilic Copolymer at the Air−Water Interface
We report a new fabrication method of a thin polymer film with regular array of micropores (honeycomb film). A honeycomb film was fabricated by depositing a dilute solution of an amphiphilic polymer on water surface. The honeycomb film transferred onto a solid substrate was characterized by atomic force microscopy. By…
Preparation of nanocrystalline ceria particles by sonochemical and microwave assisted heating methods
Nanocrystalline ceria (CeO2) particles have been successfully prepared via sonochemical and microwave assisted heating routes from aqueous solutions containing (NH4)2Ce(NO3)6, hexamethylenetetramine and poly (ethylene glycol)-19000 (PEG). The products were characterized by techniques such as powder X-ray diffraction,…
Synthesis and Characterization of High-Efficiency Nanocrystal Up-Conversion Phosphors: Ytterbium and Erbium Codoped Lanthanum Molybdate
Nanocrystal up-conversion phosphors (UCP), ytterbium- and erbium-codoped lanthanum molybdate (La 2 (MoO 4 ) 3:Yb,Er), were prepared for the first time for potential uses in bioassays especially in biochip-based analysis. The La 2 (MoO 4 ) 3:Yb,Er nanocrystals, with an average diameter of 50 nm, were prepared via a hyd…
Delamination of layered double hydroxides in polar monomers: new LDH-acrylate nanocompositesElectronic supplementary information (ESI) available: TEM image of Mg2Al(Cl) showing the layered structure. See http://www.rsc.org/suppdata/cc/b2/b204213d/
The layered double hydroxide Mg2Al(OH)6(C12H25SO4) was delaminated to give high levels of inclusion in acrylate monomers; subsequent polymerisation of the monomers containing the LDH dispersion gave polyacrylates with the inorganic component still in the delaminated form.
Coupled Atomistic and Discrete Dislocation Plasticity
A computational method for multiscale modeling of plasticity is presented wherein each dislocation is treated as either an atomistic or continuum entity within a single computational framework. The method divides space into atomistic and continuum regions that communicate across a coherent boundary, detects dislocatio…
Periodic Density Functional Theory Study of Methane Activation over La2O3: Activity of O2-, O-, O22-, Oxygen Point Defect, and Sr2+-Doped Surface Sites
Results of gradient-corrected periodic density functional theory calculations are reported for hydrogen abstraction from methane at O(s)(2-), O(s)(-), O(2)(s)(2-) point defect, and Sr(2+)-doped surface sites on La(2)O(3)(001). The results show that the anionic O(s)(-) species is the most active surface oxygen site. Th…
Synthesis of Highly Crystalline and Monodisperse Cobalt Ferrite Nanocrystals
Highly crystalline and monodisperse cobalt ferrite nanocrystals were fabricated by the high-temperature aging of a metal−surfactant complex followed by mild oxidation. Particle sizes were varied from 4 to 9 nm by changing the experimental conditions. Transmission electron microscopic (TEM) images of the particles show…
Interface Effects for Cu, CuO, and Cu2O Deposited on SiO2 and ZrO2. XPS Determination of the Valence State of Copper in Cu/SiO2 and Cu/ZrO2 Catalysts
Copper and copper oxides (Cu 2 O and CuO) have been deposited by evaporation of copper and subsequent oxidizing treatments, on the surface of flat SiO 2 and ZrO 2 substrates. Large variations of several eVs have been found in the values of the Cu 2p 3/2 binding energy (BE) and Auger parameter (α‘) of copper as a funct…
Effects of Nb and Sr doping on crystal structure of epitaxial BaTiO3 thin films on MgO substrates
Niobium (Nb) and strontium (Sr) doped barium titanate (BT) films were deposited by radio frequency (RF) magnetron sputtering with Nb and Sr doped BT ceramic targets, respectively. The effect of Nb and Sr doping on the crystal structure of epitaxial BaTiO 3 thin films on MgO substrates was investigated. The crystal str…
Synthesis and Surface Analysis of Siloxane-Containing Amphiphilic Graft Copolymers, Poly(2-hydroxyethyl methacrylate-g-dimethylsiloxane) and Poly(2,3-dihydroxypropyl methacrylate-g-dimethylsiloxane)
A series of novel amphiphilic graft copolymers having a hydrophilic poly(2-hydroxyethyl methacrylate) [poly(HEMA)] or water-soluble poly(2,3-dihydroxypropyl methacrylate) [poly(DHPMA)] backbone and hydrophobic poly(dimethylsiloxane) (PDMS) side chains have been synthesized to develop a model system to examine surface…
Elaboration de nouveaux matériaux membranaires incorporant des macrocycles tetrapyrazoliques. Etude du transport facilité des métaux alcalins Li+, Na+ et K+
La synthèse de nouveaux macrocycles tetrapyrazoliques dotés de deux bras latéraux fonctionnalisés est décrite, ces structures macrocycliques différent par la taille de la cavité macrocyclique. Les matériaux membranaires sont obtenus par photopolymérisation d'une formulation, contenant le monomère actif, étalée sur un…
Comparative analysis of Ti3SiC2 and associated compounds using x-ray diffraction and x-ray photoelectron spectroscopy
Ti 3 SiC 2 exhibits a unique combination of ceramic and metallic properties suitable for both electrical and mechanical application. With high-temperature stability, high electrical and thermal conductivity and resistance to oxidation, Ti 3 SiC 2 has proven promising as a contact layer for high power SiC semiconductor…
Cation Association with Sodium Dodecyl Sulfate Micelles As Seen by Lanthanide Luminescence
The interaction of trivalent lanthanides with sodium dodecyl sulfate micelles (SDS) in aqueous solution has been studied by a variety of experimental techniques. Potentiometric measurements with a sodium selective electrode, steady-state fluorescence spectra of Ce(III), emission lifetime measurements of Ce(III), Tb(II…
Melting and α Relaxation Effects on the Kinetics of Polypropylene Thermooxidation in the Range 80−170 °C
An isotactic polypropylene (iPP) sample (100% by FTIR) has been thermooxidized in the temperature range 80−170 °C and the kinetics of the degradation followed by measuring the chemiluminescence intensity along the induction and autoacceleration stages. From those curves, the parameter p 0, related to the initial conce…
Peroxomonosulphate initiated graft copolymerization of o‐toluidine onto nylon 6 and wool fibers—A kinetic approach
Abstract Chemical polymerization of o‐toluidine (OT) in the presence of nylon 6 and wool fibers initiated by peroxomonosulphate (PMS) in an aqueous acidic medium was carried out under nitrogen atmosphere. During the polymerization process, graft copolymers were formed along with homopolymers of OT. A procedure is give…
Effect of Chain Rigidity and Effective Conjugation Length on the Structural and Photophysical Properties of Pyridine-Based Luminescent Polymers
We report on the characterization of a number of random copolymers of “para” poly(2,5-pyridinediyl) (PPY) and “meta” poly(2,6-pyridinediyl) (PmPY). We demonstrate some ability to control the photophysical properties by variation of the ratio of the monomeric components of the copolymers. These effects, in both film an…
T g Depression in Poly( l (−)-lactide) Crystallized under Partially Constrained Conditions
A significant reduction in the glass transition temperature ( T g ) is found for poly( l -(−) lactide) (PLLA), crystallized under partially constrained conditions, where the polymer is prevented from shrinking. It is proposed that the constrained crystallization process results in increasing the net free volume in the…
Electroclinic effect and modulated phases in smectic liquid crystals
We explore the possibility that the unusually large electroclinic effect observed in the smectic-A phase of a ferroelectric liquid crystal arises from the presence of an ordered array of disclination lines and walls in a smectic-C* phase. If the spacing of these defects is in the subvisible range, this modulated smect…
Magnetic Nanocomposites Built by Controlled Incorporation of Magnetic Clusters into Mesoporous Silicates
Nanomagnets have been created by the incorporation of magnetic clusters into mesoporous silica. It is shown that, for a given cluster, the pore size has a strong influence on the degree of incorporation. Furthermore, the incorporation of these nanoclusters into three-dimensional organized mesoporous silica ensures tha…