Materials Literature
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Carbon nitride thin films have been deposited on silicon substrates, using a newly developed surface wave discharge/pulsed laser deposition system. Nitrogen incorporation in the films is examined by x-ray photoelectron spectroscopy (XPS). It shows that interaction between the laser ablated carbon species and nitrogen…
Ultraviolet (UV) light emission with almost the same peak wavelengths from thermally oxidized porous silicon (OPS) (340, 355, and 370 nm) and SiO2 powder (340, 350, and 370 nm) has been observed. Photoluminescence excitation spectra of OPS without Si nanoscale particles (SNP) and those of SiO2 powder are very similar,…
We have used digital video microscopy to study the equilibrium structure of quasi-two-dimensional suspensions of sterically stabilized uncharged polymethylmethacrylate spheres. Our experiments reveal the existence of an equilibrium hexatic phase as well as strongly first-order liquid-to-hexatic and hexatic-to-solid ph…
We calculate the distribution function of the end-to-end distance of a semiflexible polymer with large bending rigidity. This quantity is directly observable in experiments on single semiflexible polymers (e.g., DNA, actin) and relevant to their interpretation. It is also an important starting point for analyzing the…
The crystal structure of trilanthanum trichloride pyrosilicate, La3(Si2O7)Cl3, has been determined. The main building units are La(1)Cl4O5, La(2)Cl5O5 and La(3)Cl3O6 polyhedra, and Si2O7 pyrosilicate groups.
A new route for nylon-6,6 synthesis has been studied. The process is grounded on the synthesis of an α-amino ω-ester monoamide precursor (AME-6,6) easily available in reacting in the bulk hexamethylene diamine and dimethyl adipate at a low temperature (T ≅ 50°C) preferably in the presence of a phenol derivative. In su…
Two simple techniques using single-crystal specimens in polarized infrared attenuated total reflection (ATR) spectroscopy were developed for structural studies of molecular crystals, in particular of long-chain compounds. The first technique relates to a rotatory change of sample setting around the normal of the sampl…
The complexation of three kinds of sequence-ordered acid (co)polymers with a base homopolymer was studied. The acid polymers used are poly(methacrylic acid) 1, alternating (1:1) ethylene-methacrylic acid copolymer 2, and periodic (2:1) ethylene-methacrylic acid copolymer 3, and the base polymer is poly(4-vinylpyridine…
We have conducted a detailed study of Kr films adsorbed on BN. We have performed adsorption-isotherm measurements and calculations for the potential energy of Kr atoms on the surface of BN. Both the experimental and the theoretical results are extensively compared to data for Kr on graphite, as well as to data for ${\…
Pyroelectrically induced electron emission from different ferroelectric single crystals and ceramics is studied. It is observed that (Pb,La)(Zr,Ti)O3 ceramics generate rather low ferroelectric electron emission (FEE) current compared with single crystals such as triglycine sulphate and lithium niobate. Figures of meri…
In this paper a simple lattice gas model for the catalytic CO+NO→CO2+1/2N2 surface reaction is studied by means of Monte Carlo simulations. In the simulations we take into consideration the diffusion of all particles and the desorption of CO. The square and triangular lattices are used to model the surface of an ideal…
We use the $N$-point Pad\'e approximant to make the analytic continuation of the dynamic response function. This continuation scheme reproduces very efficiently the plasmon energy dispersion and the dynamic scattering cross section with double peaks for Al. For Si with covalent bondings, the energy-loss function exhib…
X-band (9.56 GHz) electron paramagnetic resonance (EPR) measurements were performed on ${\mathrm{Pb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Yb}}_{\mathit{x}}$S, ${\mathrm{Pb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Yb}}_{\mathit{x}}$Se, and ${\mathrm{Pb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm…
The gas phase downstream products of an air glow discharge have been measured, using absorption and emission spectroscopies, as a function of plasma power, air flow rate, and distance from the plasma. In addition, the reaction of these products with a linear low density polyethylene (LLDPE) polymer surface has been fo…
The characteristic mechanical behavior of bulk Ge1−xSix alloys with compositions x=0–0.4 grown by the Czochralski technique is investigated as a function of the composition and temperature by means of compressive deformation and is compared with that of elemental Ge and Si semiconductors. Both the yield stress and the…
The segmental concentration profile ρ of end-tethered flexible polymer chains is calculated for comparison with recent measurements on polymer layers having a low surface grafting density σ. Moments of ρ are also calculated as these quantities, rather than the full concentration profiles, are usually measured experime…
The nucleophilic substitution in poly(vinyl chloride) (PVC) with sodium benzenethiolate has been studied in two kinds of solvent differing in the molecular structure in the vicinity of the carbonyl group. From the evolution of the content of isotactic (mm), heterotactic (mr), and syndiotactic (rr) triads; and of mmmm,…
The recently introduced nuclear Fukui function φα is formally identified as a reactivity index of the density functional theory (according to the postulated criterion of |dμ|) and is shown to constitute the conformational contribution to a change in the molecular electronic chemical potential μ, through the relation d…
We show that at about 340 K a large (≂50%) change in the microwave absorption of a single crystal of La0.7Sr0.3MnO3 is caused by the application of a field of just a few tens of mT. This large magneto-impedance occurs at 10 GHz but is absent at 36 GHz, and we demonstrate that these results follow from the frequency an…
We report silicon band-edge photoluminescence (PL) with photon energy of 1.1 eV and external quantum efficiency (EQE) better than ${10}^{\ensuremath{-}3}$ in samples prepared by high-temperature oxidation of porous silicon. The integrated PL intensity is insensitive to temperature. The EQE strongly depends on the anne…