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。
The electronic and magnetic structures of the ${\mathrm{LaMnO}}_{3}$ compound have been studied by means of periodic calculations within the framework of spin polarized hybrid density-functional theory. In order to quantify the role of approximations to electronic exchange and correlation three different hybrid functi…
The Mott transition in a quasi-two-dimensional organic conductor, $\ensuremath{\kappa}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}\mathrm{Cu}[\mathrm{N}(\mathrm{CN}{)}_{2}]\mathrm{Cl}$ was investigated by resistance measurements under continuously controllable He gas pressure. We constructed the resis…
Nanostructured carbon films consisting of sp chains (polyynes and polycumulenes) embedded in an ${\mathrm{sp}}^{2}$ matrix are grown using supersonic carbon cluster beam deposition in ultrahigh vacuum at room temperature. All the specimens have been analyzed by in situ Raman spectroscopy. The use of different excitati…
We numerically obtain a quantitative demonstration that development of spatial correlations of mobility as temperature is lowered is responsible for the "decoupling" of transport properties of supercooled liquids. This result further demonstrates the necessity of a spatial description of the glass formation and theref…
A layered zinc hydroxide/surfactant composite was synthesized by pulsed-laser ablation of a metal Zn plate in an aqueous solution of the surfactant. The products were single-crystalline octagonal platelets with hexagonal crystal symmetry.
High quality luminescent CdS nanocrystals (NCs), with band edge emission tunable in the blue region of the visible spectrum, were synthesized by means of thermal decomposition of precursors with oleic acid as the surfactant and incorporated in optically transparent polystyrene (PS) and poly(methyl methacrylate) (PMMA)…
The transition from linear to nonlinear dynamical elasticity in rocks is of considerable interest in seismic wave propagation as well as in understanding the basic dynamical processes in consolidated granular materials. We have carried out a careful experimental investigation of this transition for Berea and Fontaineb…
High-energy (h$ν$ = 5.95 keV) synchrotron Photoemission spectroscopy (PES) is used to study bulk electronic structure of Na$_{0.35}$CoO$_{2}$.1.3H$_{2}$O, the layered superconductor. In contrast to 3-dimensional doped Co oxides, Co $\it{2p}$ core level spectra show well-separated Co$^{3+}$ and Co$^{4+}$ ions. Cluster…
We have studied the depth-dependent magnetic and structural properties of as-grown and optimally annealed ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ films using polarized neutron reflectometry. In addition to increasing the total magnetization, the annealing process was observed to produce a signif…
We present a theory of the collective orbital excitation termed orbital wave in perovskite titanates and vanadates with the triply degenerate ${t}_{2g}$ orbitals. The dispersion relations of the orbital waves for the orbital-ordered ${\mathrm{LaVO}}_{3},$ ${\mathrm{YVO}}_{3}$ and ${\mathrm{YTiO}}_{3}$ are examined in…
We have used scanning SQUID magnetometry to image vortices in ultra-thin [Ba$_{0.9}$Nd$_{0.1}$CuO$_{2+x}$]$_m$/[CaCuO$_2$]$_n$ (CBCO) high temperature superconductor samples, with as few as three superconducting CuO$_2$ planes. The Pearl lengths ($Λ= 2λ_{L}^2/d$, $λ_{L}$ the London penetration depth, $d$ the supercond…
Analytical Hartree-Fock gradients with respect to the cell parameter have been implemented in the electronic structure code CRYSTAL, for the case of three-dimensional periodicity. The code is based on Gaussian type orbitals, and the summation of the Coulomb energy is performed with the Ewald method. It is shown that a…
The kinetic behavior of a phase field model of electrochemistry is explored for advancing (electrodeposition) and receding (electrodissolution) conditions in one dimension. We previously described the equilibrium behavior of this model [J. E. Guyer, W. J. Boettinger, J. A. Warren, and G. B. McFadden, Phys. Rev. E 69,…
A diffuse interface (phase field) model for an electrochemical system is developed. We describe the minimal set of components needed to model an electrochemical interface and present a variational derivation of the governing equations. With a simple set of assumptions: mass and volume constraints, Poisson's equation,…
A family of red light-emitting star-shaped porphyrins with four monodisperse conjugated oligofluorene arms was prepared by using two key reactions: Lindsey condensation and Suzuki-Miyaura cross coupling reactions. All porphyrins exhibit high quantum yields (about 0.22) and good solubility in common organic solvents, a…
As a first step towards understanding the morphology of PdO crystals we performed a systematic full-potential density-functional theory study of all possible $(1\ifmmode\times\else\texttimes\fi{}1)$ terminations of the low-index surfaces of tetragonal PdO. Applying the concept of first-principles atomistic thermodynam…
Nanocrystalline SnO2 quantum dots were synthesized at room temperature by hydrolysis reaction of SnCl2. The addition of tetrabutyl ammonium hydroxide and the use of hydrothermal treatment enabled one to obtain tin dioxide colloidal suspensions with mean particle radii ranging from 1.5 to 4.3 nm. The photoluminescent p…
Bismuth ferrite is a magnetoelectric material, which simultaneously has polarization and spin orders. We have used electron spin resonance (ESR) as a local probe of the magnetic order in the magnetic-field range of 0--25 T, in the frequency domain of 115--360 GHz, and at a temperature of 4.2 K. The data reveal signifi…
In order to develop a yellow phosphor that emits efficiently under the 450–470 nm excitation range, we have synthesized a Eu2+-activated Sr3SiO5 yellow phosphor and attempted to develop white light-emitting diodes (LEDs) by combining them with a InGaN blue LED chip (460 nm). Two distinct emission bands from the InGaN-…
Nanoscale structural and mechanical characterization of the shell of a red abalone has been carried out. Cobble-like polygonal nanograins are basic building blocks that are used to construct individual aragonite platelets into a mother-of-pearl configuration known as nacre. The nanograin-structured aragonite platelets…