Materials Literature
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We present first-principles total-energy calculations of adsorption and reaction of molecular oxygen on the $\mathrm{ZnO}(10\overline{1}0)$ surface. We find that, on stoichiometric $\mathrm{ZnO}(10\overline{1}0)$ surfaces, the adsorption is fully molecular with a small adsorption energy and the dissociation is energet…
Abstract The optimal synthetic conditions of poly(lactic acid‐ co ‐glycolic acid) (PLGA) via melt copolycondensation directly from L ‐lactic acid ( L ‐LA) and glycolic acid (GA) with a feed molar ratio of 50/50 are discussed; the important drug‐delivery carrier PLGA50/50 is used as a special example. With reaction con…
We describe the fabrication of roselike microstructures by the direct in situ hydrothermal synthesis method. The as-prepared roselike microstructure film exhibits excellent superhydrophilic properties, absorbing a water droplet of 4 μL in less than 40 ms. Moreover, after a further modification with a self-assembled mo…
Well-aligned diluted magnetic semiconductor Zn1−xMnxO nanowires have been fabricated at 850°C from a self-formed ZnO substrate using a chemical vapor deposition method. The as-synthesized Mn-doped ZnO nanowires were characterized by field emission scanning electron microscopy and transmission electron microscopy (TEM)…
Massive fabrication of free-standing Co/Pt magnetic barcode nanowires with well-defined interfaces and layer thicknesses is obtained after freeing them from porous templates. Such barcodes display bamboo-like shapes with identical motifs either inside or out of the templates. The ferromagnetism of these barcode nanowi…
The reaction of [Mn3O(O2CR)6(py)3](ClO4) (R = Me, Et) with methyl 2-pyridyl ketone oxime (mpkoH) in a 1:3 molar ratio in MeOH/MeCN leads to [Mn3O(O2CR)3(mpko)3](ClO4) in 80-90% isolated yield. Ferromagnetic exchange interactions between the three MnIII ions in the nonplanar [MnIII3O]7+ triangular core lead to a spin g…
Colloidal Co(2+)- and Cr(3+)-doped TiO(2) nanorods and nanocrystals were synthesized and studied by X-ray powder diffraction, electronic absorption spectroscopy, magnetic circular dichroism spectroscopy, magnetic susceptibility, and transmission electron microscopy. The nanorods were paramagnetic as colloids but showe…
Time-dependent current of the electrons excited in the conduction band after ultrafast interband photogeneration is studied theoretically. The transient photocurrent is calculated for the nonlinear regime of response to a stationary electric field. The response demonstrates transient absolute negative conductivity whe…
We report the synthesis and superconducting properties of a metastable form of the known superconductor . We obtained this metastable cobaltate superconductor due to the unique way it was synthesized. Instead of using the conventional bromine-acetonitrile mixture for the -deintercalation reaction, we use an aqueous br…
We present a model for conductivity and energy diffusion in a linear chain described by a quadratic Hamiltonian with Gaussian noise. We show that when the correlation matrix is diagonal, the noise-averaged Liouville-von Neumann equation governing the time-evolution of the system reduces to the Lindblad equation with H…
Using first-principles molecular dynamics simulations, we have determined the threshold displacement energies and the associated created defects in cubic silicon carbide. We found rather anisotropic values, with an average of $19\phantom{\rule{0.3em}{0ex}}\mathrm{eV}\phantom{\rule{0.3em}{0ex}}(38\phantom{\rule{0.3em}{…
The melting of ultrathin lubricant film is studied by friction between atomically flat surfaces. The fluctuations of lubricant temperature are taken into account defined by Ornstein-Uhlenbeck process. The phase diagrams and portraits are calculated for the cases of second-order and first-order transitions -- the melti…
I analyze in details distribution of local magnetic field induced by micro- and nano-magnets. I consider three kinds of elongated magnetic islands: ellipse-, diamond- and rectangular shaped islands which were magnetized uniformly along long axis. This report concentrates on the role of their shape upon distribution of…
In this letter, we explore electron filtering as a technique to increase Seebeck coefficient and the thermoelectric power factor of heterostructured materials over that of the bulk. We present a theoretical model in which Seebeck coefficient and the power factor can be increased in an InGaAs based composite material.…
We present a first-principles study of the unreconstructed (001) surfaces of the half-metallic ferromagnet NiMnSb. Both terminations (MnSb and Ni) are considered. We find that half-metallicity is lost at the surfaces. After a discussion of the geometric relaxations and the spin-polarized surface band structure, we foc…
We perform a theoretical investigation on the time evolution of spin pulses in an $n$-type GaAs (001) quantum well with and without external electric field at high temperatures by constructing and numerically solving the kinetic spin Bloch equations and the Poisson equation, with the electron-phonon, electron-impurity…
A temperature-dependent emission is observed for CdTe nanoparticles connected to Au nanoparticles by a flexible poly(ethyleneglycol) (PEG) link acting as a molecular spring (see picture). The extension of the PEG springs varies depending on the temperature, which causes variations in CdTe emission caused by plasmon–ex…
Here, we present a systematic study on the influence of the bioligand deferoxamine mesylate on the crystallization and assembly behavior of tungsten oxide in a soft-chemistry process. Without deferoxamine mesylate, this approach yields pseudo-single crystalline tungstite nanoplatelets consisting of a large number of c…
In this article, we report the formation of dispersed anisotropic nanostructures by the oriented attachment mechanism, under hydrothermal conditions and in a system that all other growth processes are improbable. The comparison of dilute and agglomerated experimental conditions indicate that oriented attachment is an…
The instantaneous structure of the cyanide-bridged negative thermal expansion (NTE) material Zn(CN)(2) has been probed using atomic pair distribution function (PDF) analysis of high energy X-ray scattering data (100-400 K). The temperature dependence of the atomic separations extracted from the PDFs indicates an incre…