Materials Literature
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Uniform NiO, α-Fe2O3, ZnO, CuO and Ga2O3 hollow nanospheres consisting of a shell of closely packed nanoparticles with a shell wall thickness of a few tens of nanometers have been successfully synthesized on a large scale by controlled precipitation of metal cations with urea in the presence of carbonaceous saccharide…
The dielectric properties of metamaterials consisting of periodically arranged metallic nanoparticles of spherical shape are calculated by rigorously solving Maxwell's equations. Effective dielectric functions are obtained by comparing the reflectivity of planar surfaces limiting these materials with Fresnel's formula…
We report highly efficient single photon generation from InGaAs self-assembled quantum dots emitting within a two-dimensional photonic bandgap. A strongly suppressed multiphoton probability is obtained for single quantum dots in bulk GaAs and those emitting into the photonic bandgap. In the latter case, photoluminesce…
Abstract Diatoms are single‐celled micro‐algae that possess an exoskeleton (called frustule) comprised of diverse and highly ordered 3D porous silica structures and that hold considerable promise for biological or biomimetic fabrication of nanostructured materials and devices. We have used, for the first time, a soft…
We investigate the magnetocaloric properties of certain antiferromagnetic spin systems that have already been or very likely can be synthesized as magnetic molecules. It turns out that the special geometric frustration which is present in antiferromagnets that consist of corner-sharing triangles leads to an enhanced m…
Tunneling data on $\mathrm{La_{1.28}Sr_{1.72}Mn_2O_7}$ crystals confirm Coulomb interaction effects through the $\sqrt{\mathrm{E}}$ dependence of the density of states. Importantly, the data and analysis at high energy, E, show a pileup of states: most of the states removed from near the Fermi level are found between…
We present a first principles $\mathrm{LSDA}+\mathrm{U}$ study of the magnetic coupling constants in the spinel magnets $\mathrm{Co}{\mathrm{Cr}}_{2}{\mathrm{O}}_{4}$ and $\mathrm{Mn}{\mathrm{Cr}}_{2}{\mathrm{O}}_{4}$. Our calculated coupling constants highlight the possible importance of $AA$ interactions in spinel s…
Abstract The present work reports on key factors that influence the degree of order in anodic TiO 2 nanotube layers. We show that the anodization voltage and the Ti purity are of crucial importance for the ideality of self‐organization within the nanotube layers and that repeated anodization can significantly improve…
We present the results of a comparative ab initio study of single-walled SiC, BN, and BeO nanotubes (NTs) in zigzag and armchair configurations. Within density functional theory, we employ self-interaction-corrected pseudopotentials that were shown previously to yield reliable results for both structural and electroni…
Abstract Clay was introduced into single‐walled carbon nanotube (SWNT)/epoxy composites to improve nanotube dispersion without harming electrical conductivity or mechanical performance. Unlike surfactant or polymer dispersants, clay is mechanically rigid and known to enhance the properties (e.g., modulus, gas barrier,…
Electrodeposition of poly (3-hydroxyaniline) on platinum electrode from acidic/acetonitrile medium was carried out using cyclic voltammetry technique. The kinetic parameters were calculated by means of ex-situ microgravimetric and electrochemical data. The experimentally obtained kinetic equations were RP,W = kW [acid…
Abstract The work described in this paper aims at exploring the effect of reaction temperature, with and without a catalyst on the conversion and thermal properties of polyamide hot‐melt adhesives. The polyamides were synthesized from C 36 dimer acid and ethylenediamine; o ‐phosphoric acid was used as catalyst. The th…
Silica glass (SiO2) was implanted with 60keV Zn+ ions to a fluence of 1.0×1017ions∕cm2, and the chemical states were investigated along the depth in as-implanted state by x-ray excited Auger electron spectroscopy and x-ray photoelectron spectroscopy. The metallic Zn and Zn2SiO4 phases were found to have, respectively,…
Generation of the freestanding lead zirconate titanate (PZT) nanoparticles and their phase transformation behavior is investigated in this research. PZT sol-gel precursor was dried at 250°C and partially calcined at 450°C for 30min to decompose organics and bring down the free energy barrier for perovskite crystalliza…
The behavior of a Pd nanocluster on the rutile TiO2 (110) surface has been analyzed by extensive first principles molecular dynamics simulations between 100 K and 1073 K. Calculations predict a steep change in the morphological and electronic cluster structure around 800 K in excellent agreement with previous experime…
Lead fluoroborate (BO1.5–PbO–PbF2) glasses were prepared by melt quenching and studied here in terms of (micro)structural and electrical properties. The results show that electrochemically induced surface crystallization may also occur below the glass transition temperature. As previously proposed elsewhere and shown…
Large-size and high-quality (1−x)Pb(Zn1∕3Nb2∕3)O3–xPbTiO3 [PZNT(1−x)∕x] single crystals (PZNT95/5, PZNT91/9, and PZNT85/15) were grown by a modified Bridgman method using an allomeric 0.69Pb(Mg1∕3Nb2∕3)O3–0.31PbTiO3 (PMNT69/31) single crystal as a seed. At room temperature, dielectric constant and loss tangent are abo…
Switching axis: A new banana-shaped molecule forms the SmCAPA phase in the ground state and SmCSPF phase on applying an electrical field. The optic axis of such banana-shaped molecules is oriented parallel to the rubbing direction under zero-field state. The picture shows the proposed three polar structures in the B2…
Abstract A tetraarmed star‐shaped poly(methyl methacrylate) ( s ‐PMMA) was synthesized via atom transfer radical polymerization with 2‐bromoisobutyryl pentaerythritol as the initiator. For comparison, a linear PMMA with the identical molecular weight ( l ‐PMMA) was also prepared. The blends of the two PMMA samples wit…
Quasielastic central peak and acoustic anomalies in a [001] lead magnesium niobate-lead titanate single crystal have been investigated by the high-resolution micro-Brillouin scattering. Two acoustic anomalies were observed at temperatures, TC-T∼415K and TT-R∼348K. The damping showed a significant dispersion at T∼550K,…