Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
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…
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…
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…
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…
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…
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…
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…
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…
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…
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.…
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…
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…
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…
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…
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…
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…
Fluctuation microscopy is a hybrid diffraction-imaging technique that detects medium range order in amorphous materials by examining spatial fluctuations in coherent scattering. These fluctuations appear as speckle in images and diffraction patterns. The volume of material contributing to the speckle is determined by…
Papain (from papaya latex; EC 3.4.22.2) and Pronase (from Streptomyces griseus; EC 3.4.24.31) caused optimum depolymerization of chitosan at pH 3.5 and 37 degrees C, resulting in LMMC (low molecular mass chitosan) and chito-oligomeric-monomeric mixture. The yield of the latter was 14-16% and 14-19% respectively for pa…
Ultrasound, an efficient and virtually innocuous means of activation in synthetic chemistry, has been employed for decades with varied success. Not only can this high-energy input enhance mechanical effects in heterogeneous processes, but it is also known to induce new reactivities leading to the formation of unexpect…
For several centuries fluid dynamics studies have relied upon the assumption that when a liquid flows over a solid surface, the liquid molecules adjacent to the solid are stationary relative to the solid. This no-slip boundary condition (BC) has been applied successfully to model many macroscopic experiments, but has…