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。
As a representative example, nano-LiNbO3 is prepared by a wet-chemical method in order to enhance its photocatalytic activity through improving the surface area. The samples perform good crystallinity from powder x-ray diffraction and transmission-electron-microscope observations. It is surprising that photocatalytic…
Boning up on patterning: Patterned calcium carbonate films with dimensions of 200–400 μm were obtained using the photolithographic properties of a polysilane-based ABA block copolymer, PHEMA-PMPS-PHEMA. These patterns may serve as a 2D model system for CaCO3 biomaterials in which both the CaCO3 resorption by osteoclas…
Abstract Fuel processing systems that are used in conjunction with polymer electrolyte membrane (PEM) fuel cells require high activity water gas shift (WGS) catalysts that remove carbon monoxide, a poison for membranes in the fuel cell stacks. WGS activity of various noble metals supported on cubic, nanocrystalline, h…
We report here the study by optical microspectroscopy of crystalline ZnO nanoparticles produced by room-temperature organometallic synthesis. We present resonant Raman scattering spectrum obtained from different sized nanostructures from which the longitudinal-optical (LO) phonon frequency has been found to be very we…
The kinetic model of stepwise polymerization is revisited, with some adaptations for its application to the kinetics of oriented attachment of nanoparticles in colloidal suspensions, which results in the formation of anisotropic particles. A comparison with experimental data reported in the literature shows good agree…
It is well known that nitrogen forms aggregates in diamond. However, little is known regarding aggregation of boron, an impurity that can be incorporated in very high concentrations. In this paper we present the results of first-principles calculations regarding the structure and properties of boron-aggregates, and si…
Empirical tight-binding simulations of the band structure of $1T\text{\ensuremath{-}}{\mathrm{TaS}}_{2}$ reveal that the combination of spin-orbit coupling and the low-temperature $\sqrt{13}\ifmmode\times\else\texttimes\fi{}\sqrt{13}$ reconstruction generates a distinct and very narrow band at the Fermi level. Spin-or…
We developed transparent 3.5mol% Ho3+-doped oxyfluoride nano-glass-ceramics, where the Ho3+-dopants dissolve in the 6nm diameter β-PbF2 nanocrystals. The cubic site of Ho3+ and a low vibration frequency of its PbF2 environment result in an intense and 50nm broad emission band I65→I85 of Ho3+ at 1.2μm with a temperatur…
Kinetics of oxidation of MgO–C refractory bricks containing 14.3% graphite, 80.9% magnesia, and 4.8% phenolic resin is investigated comprehensively. Effect of temperature and grain size distribution on the rate of oxidation of graphite is evaluated by application of a mathematical model developed on the basis of shrin…
The correlation-driven metal-insulator transition (MIT) of BaVS$_3$ was studied by polarized infrared spectroscopy. In the metallic state two types of electrons coexist at the Fermi energy: The quasi 1D metallic transport of $A_{1g}$ electrons is superimposed on the isotropic hopping conduction of localized $E_g$ elec…
Using neutron elastic and inelastic scattering and high-energy x-ray diffraction, we present a comparison of $40%\phantom{\rule{0.3em}{0ex}}\mathrm{Pb}({\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}){\mathrm{O}}_{3}\text{\ensuremath{-}}60%\phantom{\rule{0.3em}{0ex}}{\mathrm{PbTiO}}_{3}$ (PMN-60PT) with pure $\mathrm{Pb}({\mat…
A detailed reexamination of the (110) surface structure of rutile ${\mathrm{TiO}}_{2}$ has been carried out using first-principles total-energy methods. This investigation is in response to a recent high-precision quantitative low-energy electron diffraction (LEED-IV) measurement revealing certain significant quantita…
Structural studies on ultrathin SrRuO3∕BaTiO3∕SrRuO3 capacitors, with BaTiO3 thicknesses of between 5nm and 30nm, show well-defined interfaces between ferroelectric BaTiO3 and electrode SrRuO3 layers. In these capacitors, we cannot observe any extrinsic electrical effects due to either the formation of an insulating i…
Distribution function and current density in a one-dimensional superlattice with parabolic miniband are calculated. The current dependence on the temperature coincides with experimental data. Generalization is carried out to quasi-two-dimensional superlattice with paraboloidal miniband. For a sample opened in Y direct…
We examine different models and methods for studying finite-temperature magnetic hysteresis in nanoparticles and ultrathin films. This includes micromagnetic results for the hysteresis of a single magnetic nanoparticle which is misaligned with respect to the magnetic field. We present results from both a representatio…
The Portevin-Le Chatelier (PLC) effect is a kind of plastic instability observed in many dilute alloys when deformed at certain ranges of strain rate and temperature. In this letter we establish that the dynamical process responsible for the PLC effect is Poisson in nature by applying statistical analysis to the obser…
By solving the equilibrium equations for a polymer in a neutral polymer brush, the degree of interpenetration of two polymer brushes in contact and near contact is calculated. These results are used to calculate values of the force of static friction in agreement with recent friction measurements for polymer brush lub…
We have proposed an efficient parameterization method for a recent variant of the Gay-Berne potential for dissimilar and biaxial particles and demonstrated it for a set of small organic molecules. Compared to the previously proposed coarse-grained models, the new potential exhibits a superior performance in close cont…
The shifts of ferroelectric phase transition temperatures and domain stabilities of BaTiO3 thin films as a function of strain and temperature were studied using phase-field simulations. A new Landau-Devonshire thermodynamic potential based on an eighth-order polynomial was employed for describing the bulk free energy…
Periodic ab initio density functional calculations on ultrathin films of AlN, BeO, GaN, SiC, ZnO, and ZnS demonstrate the stabilization of thicker films terminating with the polar {0001} surface via charge transfer and metallization of the surface layers. In contrast thinner films remove the dipole by adopting a graph…