Materials Literature
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Novel ring-disk ultramicroelectrodes (RD-UMEs) with analytical tip diameters as small as 25-30 microns were fabricated. Carbon RD-UMEs were reproducibly prepared by the chemical vapor deposition of alternating concentric layers of silica and carbon on resistively heated 10 microns carbon fibers. High-quality films wit…
Strained CdSe/CdS superlattices show very strong intrinsic piezoelectric fields due to the high piezoelectric constants in combination with a large lattice mismatch of 3.9%. The linear as well as the nonlinear optical properties are formed by these fields, which dominate the band structure. We report on the excitation…
Steady-state- and time-resolved-photoluminescence (PL) and cathodoluminescence (CL) studies have been carried out on several synthetic type-IIb boron-doped semiconducting diamond samples. The behavior of the 1.84-eV red donor-acceptor pair band is compared directly with that of the well-known green band-A emission nea…
This work reports a successful electron-electron coincidence experiment performed in grazing-angle reflection geometry. (e,2e) measurements with a 300-eV impact energy have been carried out on a clean highly oriented pyrolytic graphite surface and the feasibility of binding-energy spectroscopy with quasimomentum discr…
We present and discuss photoemission (PES) and O 1s x-ray-absorption spectra (XAS) of ${\mathrm{Ti}}_{4}$${\mathrm{O}}_{7}$ taken at different temperatures in the range 50--300 K. The PES taken at 300 K show Ti 3d bands at the Fermi level and O 2p bands at higher binding energies. The Ti 3d bands shift approximately 0…
Abstract The Monte Carlo sampling technique is used to investigate the branched structure formation during free‐radical polymerization that involves chain transfer to polymer. This method accounts for the history of the generated branched structure and can provide virtually any structural information, because one can…
Abstract Polyethylene–polystyrene blends containing small amounts of polyethylene (20 wt %) display a cocontinuous phase morphology that is very unstable in the absence of an emulsifier. The kinetics of coalescence at high temperature is therefore very sensitive to differences in the interfacial activity of added poly…
Abstract Crystallization behavior of synthetic cis ‐1,4 polyisoprene mixed with methyl linolate was investigated by differential scanning calorimetry and dilatometry. At isothermal crystallization temperature of −25°C, a rate of crystallization decreased with the addition of 1 wt % methyl linolate, whereas it increase…
The local empirical pseudopotential theory in the S-matrix implementation was used to study the structure of (Zn,Cd)(S,Se) polytypes considered as natural heterocrystalline superlattices. Hexagonal polytype superlattices of (Zn,Cd)(S,Se) are predicted to be characterized by direct band gaps and have minibands derived…
Thermal annealings of amorphous gallium antimonide films were accompanied using Raman spectroscopy, both for stoichiometric and nonstoichiometric compositions. The films were prepared by flash evaporation on silicon substrates. Structural changes were induced by the heat treatments: an increasing degree of crystalliza…
Compositional ordering in ${\mathrm{Si}}_{0.5}$${\mathrm{Ge}}_{0.5}$ alloy films grown epitaxially on Si(001) substrates was investigated using four-circle x-ray-diffraction measurements. Thin-film alloy samples grown by molecular-beam epitaxy, as well as a sample grown by pulsed chemical vapor deposition were studied…
Magnetic properties and the hyperfine magnetic fields at 55 Mn in ferromagnetic oxides La(Co 2+ 1- x Mg x 2+ ) 0.5 Mn 0.5 4+ O 3 (0≤ x ≤0.4) are studied. The exchange integral, J , for the superexchange interaction between neighboring Mn 4+ and Co 2+ ions is found to be +15.3 K in magnitude. 55 Mn NMR spectra, compose…
Single-crystal metallic cubic sodium-tungsten bronzes ${\mathrm{Na}}_{\mathit{x}}$${\mathrm{WO}}_{3}$ (x\ensuremath{\ge}0.25) and ${\mathrm{Na}}_{\mathit{x}}$${\mathrm{Ta}}_{\mathit{y}}$${\mathrm{W}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{O}}_{3}$ (x-y=0.42) and monoclinic reduced ${\mathrm{WO}}_{3\mathrm{\ens…
Dielectric dispersion was observed in a single crystal with the composition of ErFe 2 O 3.95 below magnetic transition temperature. It is characterized by a large dielectric constant of the order of 10 4 , and a Debye-type frequency dependence like in the polycrystalline samples of the same substance which we reported…
Electronic structures of the Heusler compounds, NiMnSb and PtMnSb, are investigated by using the linearized-muffin-tin-orbital band method. Equilibrium properties such as lattice constants and bulk moduli are obtained from total energy calculations and effects of the spin-orbit interaction on electronic structures and…
The influence of hydrogen incorporation on the microstructure of hydrogenated amorphous carbon (a-C:H) films has been studied in detail by applying several complementary methods, i.e., elastic recoil detection analysis (ERDA), hydrogen evolution, and infrared absorption measurements, to two series of samples prepared…
Ferroelectric lead zirconate titanate thin films of morphotropic phase boundary composition were fabricated through the sol-gel spin-on technique to study the thickness dependence of electrical characteristics. At saturation, the films exhibited a dielectric constant of 1300, dissipation factor of 0.03, Curie temperat…
Scanning tunneling microscopy has been used to investigate the structure of ${\mathrm{TiO}}_{2}$(110) as a function of oxygen-vacancy density. The results are consistent with imaging Ti atoms, as expected given the positive sample bias employed. Our results for the stoichiometric 1\ifmmode\times\else\texttimes\fi{}1 s…
It has been shown in a recent analysis of the temperature dependence of the dc conductivity of the quasi-one-dimensional conductor (fluoranthene${)}_{2}$${\mathrm{PF}}_{6}$ that in spite of the occurrence of the Peierls transition to a charge-density-wave ground state (formally implicating polarons as excitations), th…
The possibility of the existence of a spontaneous relaxor-normal ferroelectric transition was proposed and examined using Pb(Ni1/3Nb2/3)O3-PbTiO3-PbZrO3 (PNN-PT-PZ) pseudoternary system across the morphotropic phase boundary (MPB). On cooling, the PNN-PT-PZ system in the tetragonal-rich side of the MPB underwent a spo…