Sune Nygaard、Bo W. Laursen、Amar H. Flood 等 6 位作者2005-10-10Chemical Communications
A highly constrained [2]rotaxane, constructed in such a way that the tetracationic cyclobis(paraquat-p-phenylene) ring is restricted to reside on a monopyrrolotetrathiafulvalene unit, has been synthesised and characterised. This design allows the deslipping free energy barrier for the tetracationic ring in all three r…
Electron Spin Resonance StudiesMagnetism in coordination complexesOrganic and Molecular Conductors Research
A.S.J. Suiker、René de Borst2005-10-10Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences
This article discusses the derivation of continuum models that can be used for modelling the inhomogeneous mechanical behaviour of granular assemblies. These so-called kinematically enhanced models are of the strain-gradient type and of the strain-gradient micro-polar type, and are derived by means of homogenizing the…
Composite Material MechanicsRock Mechanics and ModelingNonlocal and gradient elasticity in micro/nano structures
D. E. Markov、Paul W. M. Blom2005-10-10Physical Review B
The dynamics of exciton quenching in a conjugated polymer due to the presence of metal films is analyzed using time-resolved photoluminescence. The quenching is governed by direct radiationless energy transfer to the metal and is further enhanced by diffusion of excitons into the depletion area of the exciton populati…
Conducting polymers and applicationsOrganic Light-Emitting Diodes ResearchOrganic Electronics and Photovoltaics
А. В. Алексеева、В. А. Богатырев、Л. А. Дыкман 等 7 位作者2005-10-10Applied Optics
We describe optical monitoring of the synthesis of gold nanorods (NRs) based on seed-mediated growth in the presence of the soft surfactant template cetyltrimethyilammonium bromide. To separate NRs from spheres and surfactants we fractionated samples in the density gradient of glycerol. The optical properties of NRs w…
Gold and Silver Nanoparticles Synthesis and ApplicationsNanocluster Synthesis and ApplicationsNanoparticle-Based Drug Delivery
Qian Wang、Qiang Sun、Puru Jena2005-10-10Physical Review Letters
Using density functional theory we show that the magnetic coupling of Mn atoms in the nanowires, unlike that in the thin film, is ferromagnetic. This ferromagnetic coupling, brought about due to the confinement of electrons in the radial direction and the curvature of the Mn-doped GaN nanowires' surface, is mediated b…
ZnO doping and propertiesMagnetic properties of thin filmsGaN-based semiconductor devices and materials
Valérie Buissette、Domitille Giaume、Thierry Gacoin 等 4 位作者2005-10-10Journal of Materials Chemistry
Besides well-known quantum dots, lanthanide-doped oxide nanocrystals form a new promising class of nanophosphors. Lanthanide vanadate and phosphate nanoparticles are prepared as well-dispersed and highly concentrated colloids by a very simple aqueous route, using competition between precipitation and complexation reac…
Nanocluster Synthesis and ApplicationsQuantum Dots Synthesis And PropertiesLuminescence Properties of Advanced Materials
D. T. Hristopulos、L. Leonidakis、A. Tsetsekou2005-10-10arXiv
The evolution of grain structures in materials is a complex and multiscale process that determines the material's final properties. Understanding the dynamics of grain growth is a key factor for controlling this process. We propose a phenomenological approach, based on a nonlinear, discrete mass transfer equation for…
Materials Science
T. Klimczuk、H. W. Zandbergen、N. M. van der Pers 等 7 位作者2005-10-10arXiv
The high pressure synthesis, structure and magnetic properties of Ca_25Co_22O_56(OH)_28 are reported. The compound has a misfit structure, consisting of double, square calcium oxide hydroxide rock-salt-like layers between hexagonal CoO_2 layers. The misfit compound crystallizes in the monoclinic space group C2/m, and…
Materials Science
Andreas Menzel、Yuriy V. Tolmachev、Kee-Chul Chang 等 7 位作者2005-10-10arXiv
Polarization dependence of resonant anomalous surface x-ray scattering (RASXS) was studied for interfaces buried in electrolytes or in high-pressure gas. We demonstrate that RASXS exhibits strong polarization dependence when the surface is only slightly modified by adsorption of light elements such as carbon monoxide…
Materials Science
Sampsa Riikonen、Daniel Sanchez-Portal2005-10-10arXiv
We present a systematic study of the atomic and electronic structure of the Si(111)-(5x2)-Au reconstruction using first-principles electronic structure calculations based on the density functional theory. We analyze the structural models proposed by Marks and Plass [Phys. Rev. Lett.75, 2172 (1995)], those proposed rec…
Materials Science
Daniel Sanchez-Portal、Sampsa Riikonen、Richard M. Martin2005-10-10arXiv
Our it ab initio calculations show that spin-orbit coupling is crucial to understand the electronic structure of the Si(557)-Au surface. The spin-orbit splitting produces the two one-dimensional bands observed in photoemission, which were previously attributed to spin-charge separation in a Luttinger liquid. This spin…
Materials Science
Sampsa Riikonen、Daniel Sanchez-Portal2005-10-10arXiv
Recent photoemission experiments on the Si(553)-Au reconstruction show a one-dimensional band with a peculiar ~1/4 filling. This band could provide an opportunity for observing large spin-charge separation if electron-electron interactions could be increased. To this end, it is necessary to understand in detail the or…
Materials Science
Andreas Menzel、Kee-Chul Chang、Vladimir Komanicky 等 7 位作者2005-10-10arXiv
Resonance anomalous surface x-ray scattering (RASXS) technique was applied to electrochemical interface studies. It was used to determine the chemical states of electrochemically formed anodic oxide monolayers on platinum surface. It is shown that RASXS exhibits strong polarization dependence when the surface is signi…
Materials Science
Shengqiang Zhou、A. Vantomme、B. S. Zhang 等 5 位作者2005-10-10arXiv
With the aim of investigating the possible integration of opto-electronic devices, epitaxial GaN layers have been grown on Si(111) SOI and on Si/CoSi2/Si(111) using metalorganic chemical vapor deposition. The samples are found to possess a highly oriented wurtzite structure, a uniform thickness and abrupt interfaces.…
Materials Science
J. E. Prieto、O. Krupin、S. Gorovikov 等 6 位作者2005-10-10arXiv
The epitaxial system Sm/Co(0001) was studied for Sm coverages up to 1 monolayer (ML) on top of ultrathin Co/W(110) epitaxial films. Two ordered phases were found for 1/3 and 1 ML Sm, respectively. The valence state of Sm was determined by means of photoemission and magnetic properties were measured by magneto-optical…
Materials Science
Pavel A. Belov、Constantin R. Simovski2005-10-10arXiv
The problem of plane-wave diffraction on semi-infinite orthorhombic electromagnetic (photonic) crystals of general kind is considered. Boundary conditions are obtained in the form of infinite system of equations relating amplitudes of incident wave, eigenmodes excited in the crystal and scattered spatial harmonics. Ge…
Materials Science
Eu Jin Tan、Mathieu Bouville、Dong Zhi Chi 等 8 位作者2005-10-10arXiv
A new pyramidal structural defect, 5 to 8 micron wide, has been discovered in thin films of epitaxial erbium disilicide formed by annealing thin Er films on Si(001) substrates at temperatures of 500 to 800C. Since these defects form even upon annealing in vacuum of TiN-capped films their formation is not due to oxidat…
Materials Science
Alexander Schnurpfeil、Bo Song、Martin Albrecht2005-10-10arXiv
We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wave function based full ab initio description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green's funct…
Strongly Correlated ElectronsMaterials Science
Wataru Fujita、Ryusuke Kondo、Seiichi Kagoshima 等 4 位作者2005-10-10arXiv
We have studied the crystal structure and magnetic properties of the organic radical cation salt, BBDTA-InCl4. This material formed a one-dimensional coordination polymer, whose structure was characteristic of inorganic spin-Peierls materials. Magnetic measurements indicated the spin-Peierls transition like behavior a…
Materials Science
D. P. Makhnovskiy、L. V. Panina2005-10-10arXiv
New types of tunable composite materials are considered, the effective microwave permittivity of which may depend on an external dc magnetic field or tensile stress. The composites consist of short pieces of conductive ferromagnetic microwires embedded into a dielectric matrix. The short wire inclusions play a role of…
Materials Science