Materials Literature
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The electronic band structure for electrons bound on periodic minimal surfaces is differential-geometrically formulated and numerically calculated. We focus on minimal surfaces because they are not only mathematically elegant (with the surface characterized completely in terms of ``navels'') but represent the topology…
We report neutron inelastic scattering measurements of the lowest-energy transverse optic (TO) phonon branch in the relaxor Pb(Mg1/3Nb2/3)O3 from 400 to 1100 K. Far above the Burns temperature T(d) approximately 620 K we observe well-defined propagating TO modes at all wave vectors q, and a zone center TO mode that so…
A system of strongly interacting electron-lattice polarons can exhibit charge and orbital order at sufficiently high polaron concentrations. In this study, the structure of short-range polaron correlations in the layered colossal magnetoresistive perovskite manganite ${\mathrm{La}}_{1.2}{\mathrm{Sr}}_{1.8}{\mathrm{Mn}…
The analysis of the roughness of B<SUB>4</SUB>C films of different thickness as well as W/B<SUB>4</SUB>C multilayer mirrors of different periods is performed basing on AFM and x-ray scattering (XRS) measurements. It is demonstrated that the linear model of a film growth is able to describe the whole set of experimenta…
The photoconductivity (PC) spectra of the compounds CH 3 NH 3 PbI 3 , [CH 3 NH 3 ][CH 3 C 6 H 4 CH 2 NH 3 ] 2 Pb 2 I 7 , [CH 3 C 6 H 4 CH 2 NH 3 ] 2 PbI 4 , [H 2 NC(I)=NH 2 ] 3 PbI 5 as well as the spectra of similar compounds bases on C 10 H 21 SC(NH 2 ) 2 , H 3 N(CH 2 ) 6 NH 3 , C 14 H 9 CH 2 SC(NH 2 ) 2 , SnI 4 , P…
We have investigated the magnetic and transport properties of the Gd-doped layered manganite $({\mathrm{La}}_{0.8}{\mathrm{Gd}}_{0.2}{)}_{1.4}{\mathrm{Sr}}_{1.6}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}.$ The Gd-doped compound shows the nonmetallic spin-glass-like state below 30 K, driven by competing interaction between the…
Visible photoluminescence at 515 nm of ruthenium-doped multiwall carbon nanotubes, fabricated on quartz substrates using a chemical vapor deposition technique, is reported. The well-aligned nanotubes serve as templates for the luminescent, residual ruthenium–iron catalyst particles contained within the nanotubes, rest…
A wavelength-multiplexed optical scanning scheme is proposed for deflecting a free-space optical beam by selection of the wavelength of the light incident on a wavelength-dispersive optical element. With fast tunable lasers or optical filters, this scanner features microsecond domain scan setting speeds and large- dia…
We use the Leslie–Ericksen theory to simulate the shear flow of tumbling nematic polymers. The objectives are to explore the onset and evolution of the roll-cell instability and to uncover the flow scenario leading to the nucleation of disclinations. With increasing shear rate, four flow regimes are observed: stable s…
Abstract Previously, isotactic, atactic, and syndiotactic poly(methyl methacrylates) (PMMAs) (designated as iPMMA, aPMMA, and sPMMA) were mixed with poly(vinyl phenol) (PVPh) separately in tetrahydrofuran (THF) to make three polymer blend systems. According to calorimetry data, iPMMA was found to be miscible with PVPh…
ZnSe nanocrystals are prepared in water by a wet chemistry method. By selecting an appropriate pH value and surface-capping agents, a whitish blue fluorescence peaking at 470 nm is observed under ZV irradiation. The intensity of this fluorescence increases dramatically under reflux and saturates after ~ 40 hrs. The fi…
Abstract Mn(II) ion binds to human serum albumin (HSA) through one strong binding site ( K A = 7.9 × 10 3 M −1 ) and several weaker binding sites. Through competition assays it has been shown that the strong binding site lies in a region which has been previously identified as the Cd(II) Zn(II) site. The binding of M…
Abstract Hard segment hydrogen bonding interactions in a particular polyurethane segmented copolymer have been analysed through a viscometric approach to determine the behaviour of polyurethane solutions with different solvent compositions. Analysis of log η sp versus log c [ η ] master curves (solely comprising dilut…
The in situ measurement capabilities and advantages of recently developed spectroscopic ellipsometry (SE) instrumentation, which covers wide spectral ranges (190-1700 nm, or 0.73-6.5 eV) and is based on rotating-compensator technology, are described. A technique which can quantitatively correct for window birefringenc…
Chemical ordering of the B-site cations in undoped, 5, 10, 20, and 30 mol % La3+-doped Pb(Mg1/3Nb2/3)O3 (PMN) ceramics with perovskite structure, has been examined by Raman scattering. Two B-site chemical ordering models, the space-charge model, and the random layer model assume a space group of Fm3̄m for the ordered…
CdSe, InP, and ZnO colloidal quantum dots of 1.5--2.5 nm radius show 3 meV homogeneous width at 10 K for the midinfrared ${1S}_{e}{\ensuremath{-}1P}_{e}$ intraband transition around 300 meV. A weak temperature dependence leads to a homogeneous width of less than 10 meV at 200 K for 2.3 nm radius CdSe. The strength of…
The coupling of a semimetallic carbon nanotube to a surface acoustic wave (SAW) is proposed as a vehicle to realize quantized adiabatic charge transport. We demonstrate that electron backscattering from a periodic SAW potential can be used to induce a miniband spectrum at energies near the Fermi level. Within the fram…
Abstract Star‐shaped low molecular weight poly(ε‐caprolactone)s (PCLs) were synthesized and functionalized with crosslinkable terminal groups for subsequent crosslinking. The ε‐caprolactone (CL) prepolymers were polymerized by ring‐opening in the presence of polyglycerine (PGL) as an initiator (1, 3 and 5 mol%) and Sn…
Abstract Two different biodegradable polyesters [polycaprolactone (PCL) and poly(3‐hydroxybutyrate ‐co‐ valerate) (PHBV)] were blended with a maize starch that had high amylose content through the use different reactive approaches. The compatibilization of both systems was obtained. PCL/starch composites were obtained…
Silicon nanocrystals were prepared by laser pyrolysis of silane in a gas flow reactor and deposited on substrates by cluster beam deposition. The evolution of the photoluminescence was measured as a function of the time the samples were exposed to air. With gradual air exposure and oxidation, the photoluminescence inc…