Materials Literature
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We present a first-principles computational study of the nature and origin of ferromagnetism in Co-doped $\mathrm{Ti}{\mathrm{O}}_{2}$. We calculate the magnetic ordering and electronic properties as a function of the concentration and distribution of Co dopants and oxygen vacancies. We find that Co atoms prefer to su…
We present a novel approach to the in situ deposition of size-controlled platinum nanoparticles on the exterior walls of carbon nanotubes (CNTs). The reduction of metal ions in ethylene glycol (EG), by the addition of a salt such as sodium dodecyl sulfate (SDS), p-CH3C6H4SO3Na, LiCF3SO3, or LiClO4, results in high dis…
Silver nanowire arrays with high aspect ratios have been prepared using potentiostatic electrodeposition within the confined nanochannels of a commercial porous anodic aluminium oxide template. The nucleation and growth processes are intensively studied by current versus time transients. Scanning electron microscopy r…
The purpose of this study is to elucidate the interaction between the cell and the surface of poly(L-lactide) (PLLA) samples, which were modified using a low-temperature plasma treatment apparatus at atmospheric pressure. The plasma treatments were carried out in the atmospheres of air, carbon dioxide (CO2), and perfl…
We investigate the phenomenon of multilayer formation via layer-by-layer deposition of alternating charge polyelectrolytes. Using mean-field theory, we find that a strong short-range attraction between the two types of polymer chains is essential for the formation of multilayers. The dependence of the required short-r…
Circular or columnar orientations of mesoporous silica can be selectively prepared by tuning the silica-to-surfactant ratio and the humidity during the synthesis of the mesoporous material within the regular larger channels of anodic alumina membranes. The transmission electron microscopy image shows the circular orie…
OBJECTIVE: Assess effects of body mass index (BMI) on trial of labor after previous cesarean delivery and determine whether morbidly obese women have greater maternal and perinatal morbidity with trial of labor compared with elective repeat cesarean delivery. METHODS: Secondary analysis from a prospective observationa…
Recent experiments involving CdTe films grown on Si(111) substrates by hot wall epitaxy revealed features not previously observed [S. O. Ferreira \textit{et al.}, J. Appl. Phys. \textbf{93}, 1195 (2003)]. This system, which follows the Volmer-Weber growth mode with nucleation of isolated 3D islands for less than one m…
We have used in-field neutron and x-ray single-crystal diffraction to measure the incommensurability $\ensuremath{\delta}$ of the crystal and magnetic structures of multiferroic ${\mathrm{TbMnO}}_{3}$. We show that the flop in the electric polarization at the critical field ${H}_{C}$, for field $H$ along the $a$ and $…
X-ray diffraction and Raman scattering studies on scheelite structured barium molybdate show that, at 5.8 GPa, it undergoes a first order phase transition to fergusonite structure (I2/a, Z=4), asobserved in iso-structural barium tungstate.At still higher pressures, barium molybdate transform to another phase between 7…
Abstract Novel three‐dimensional (3D) hierarchical nanoarchitectures of ϵ‐MnO 2 have been synthesized by a simple chemical route without the addition of any surfactants or organic templates. The self‐organized crystals consist of a major ϵ‐MnO 2 dipyramidal single crystal axis and six secondary branches, which are arr…
The physical origin of cuprate high-temperature superconductor pseudogaps remains debatable. We point out that the indication of such excitation is hidden in the usual expression for the quasiparticle energy. It can be realized on a suitable multiband spectrum with an interband pairing channel. The band components bea…
We report a simple safe and attractive pedagogic demonstration with magnetic compasses that facilitates an intuitive understanding of the concept that ferromagnetism and ferroelectricity do not result from dipole-dipole interactions alone. Phonon dispersion relations were calculated for a 3-dimensional simple-cubic di…
Abstract Highly ordered mesoporous silicon carbide ceramics have been successfully synthesized with yields higher than 75 % via a one‐step nanocasting process using commercial polycarbosilane (PCS) as a precursor and mesoporous silica as hard templates. Mesoporous SiC nanowires in two‐dimensional (2D) hexagonal arrays…
Keeping it in the family: A one-pot condensation with a boric acid template leads to the synthesis of subporphineboron(III) complexes (see example; B green, O red, N blue, C turquoise, H white), ring-contracted congeners of porphyrins. Facile axial ligand exchange reactions provide alkoxy- and carboxy-coordinated subp…
Benign belts: Single-crystalline gold nanobelts (see SEM image) can be synthesized by ultrasound irradiation of an aqueous solution of HAuCl4 containing α-D-glucose as a biological directing agent. The gold nanobelts are typically 30–50 nm wide and several micrometers long. The method is simple, rapid, and avoids haza…
A wide variety of monomeric and oligomeric, donor-substituted 1,1,4,4-tetracyanobutadienes (TCBDs) have been synthesized by [2+2] cycloaddition between tetracyanoethylene (TNCE) and donor-substituted alkynes, followed by electrocyclic ring opening of the initially formed cyclobutenes. Reaction yields are often nearly…
First-principles density functional and quantum Monte Carlo calculations of light-element doped fullerenes reveal significantly enhanced molecular H2 binding for substitutional B and Be. A nonclassical three-center binding mechanism between the dopant and H2 is identified, which is maximized when the empty p(z) orbita…
This article describes an electrospinning process to fabricate double-layered ultrafine fibers. A bioabsorbable polymer, Polycaprolactone (PCL), was used as the outer layer or the shell and two medically pure drugs, Resveratrol (RT, a kind of antioxidant) and Gentamycin Sulfate (GS, an antibiotic), were used as the in…
The vibrational spectra of the heteropoly acids can be conveniently regarded as composed of contributions from the polyoxometalate anion (the primary structure) and from the water of crystallisation and hydrated protons (the secondary structure). Following a brief general survey of vibrational spectra of hydrogen-bond…