Materials Literature
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The third-order nonlinear optical (NLO) response of colloidal “quantum-dot” cadmium sulfide (CdS) nanocrystals has been measured both in solution and in Langmuir−Blodgett (L−B) multilayers of a polydiacetylene (PDA) “alloy” NLO polymer. The PDA “alloy” was composed of a tailored mixture of diacetylene monomers having…
The interlayer magnetoresistance of the quasi-two-dimensional metal $\ensuremath{\alpha}\ensuremath{-}{(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\mathrm{T}\mathrm{T}\mathrm{F})}_{2}{\mathrm{KHg}(\mathrm{SCN})}_{4}$ is considered. In the temperature range from 0.5 to 10 K and for fields up to 10 T the magn…
Transient absorbance changes following nanosecond flash excitation of M 4 [W 10 O 32 ] (M = Na + or ( n -C 4 H 9 ) 4 N + ≡ Q + ) in acetonitrile reveal a long-lived ligand-to-metal charge-transfer (LMCT) intermediate [W 10 O 32 ] 4-† (φ ∼ 0.50, τ > 74 ns) as the reactive species in photocatalyzed organic oxidations. F…
The electronic properties of CaFe 1- x Co x O 3 , a perovskite system dominated by oxygen-hole character, were studied experimentally. A partial Co-substitution has been found to induce a serial transformation from a charge-disproportionated, antiferromagnetic (AF), insulating phase (Phase I, x <0.1) to a charge-melte…
Thermal transitions of type I collagen fibrils were investigated by differential scanning calorimetry and spectrophotometry of turbidity within a wide range of external conditions. The advanced microcalorimeter allowed us to carry out the measurements at low concentrations of collagen (0.15-0.3 mg/mL). At these concen…
Techwire Using the URL at the [end][1] of this item, readers can immediately offer feedback and suggestions on this topic. I t has always been a dream of materials researchers [[HN1][2]] to design a new material completely on paper, optimizing the composition and processing steps in order to
Irradiation of a THF solution containing Mn 2 (CO) 10 and 3,6-di- tert -butyl-1,2-benzoquinone (3,6-DBBQ) gave dark green crystals of Mn(thf) 2 (3,6-DBQ) 2 . Structural characterization has shown that the inner coordination geometry about the metal has the axially elongated trans structure that appears characteristica…
Novel hyperbranched poly(ε-caprolactone)s have been synthesized. The versatile synthesis utilizes AB 2 macromonomers and allows the thermo-physical properties of the polymers to be tailored. The ε-caprolactone-based AB 2 macromonomers were synthesized through living ring opening polymerization, using aluminum benzylox…
We present a theoretical study of the influence of solvent on ordered block copolymer solutions. The phase behavior is examined as a function of solvent selectivity, temperature, copolymer concentration, composition, and molecular weight. Phase maps are constructed using self-consistent mean-field (SCMF) theory, via t…
A para→ferroelectric stress-free transition in a random field of static defects is studied by the computer simulation method. It is shown that the electrostatic dipole–dipole interaction may produce in the ferroelectric transition the same “martensitelike” effects as the strain-induced interaction in the martensitic t…
The fine structure in the CdSe nanocrystal absorption spectrum is computed by incorporating two-particle electron-hole interactions and spin-orbit coupling into a tight-binding model, with an expansion in electron-hole single-particle states. The exchange interaction and spin-orbit coupling give rise to dark, low-lyin…
Boron suboxide, nominally B 6 O, was synthesized by reducing B 2 O 3 with B up to 10 GPa in a multianvil press at temperatures between 1200 and 1800 °C. The samples were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and parallel electron energy-loss spectros…
The carbon $1s$ core levels of diamond (100) and (111) surfaces were investigated using high-resolution photoelectron spectroscopy. The surfaces were prepared in a hydrogen plasma, which is known to result in atomically flat surfaces. From the signature of the C $1s$ core-level spectra, four different surface terminat…
In this paper, the influence of solvents on the first hyperpolarizability β of nonlinear optical (NLO) molecules is studied at 25 °C for solutions of p-nitroaniline and N,N-dimethyl paranitroaniline in some 50 solvents belonging to different classes. The hyperpolarizabilities deduced from measured hyper-Rayleigh scatt…
We present a photoemission and x-ray-absorption study on boron carbide which identifies the spectroscopic features of this material, discussing them in connection with current structural models. A study on the surface thermal stability is also performed, revealing that despite the high melting point of boron carbide $…
The magnetic susceptibility and high-field magnetization process of NH 4 CuCl 3 with double chains of CuCl 3 have been measured using single crystals. No anomaly indicative of the three-dimensional ordering is observed in susceptibility data above 1.7 K. It is found, by magnetization measurement down to 0.5 K, that in…
Time-resolved two-photon photoemission (2PPE) at various photon energies is used to investigate the relaxation dynamics of hot electrons in Cu(111), applying auto- and cross-correlation techniques. The relaxation times vary from 250 fs at 0.1 eV above the Fermi level to 20 fs at 2 eV and show a strong wavelength depen…
We present results of all-electron electronic-structure calculations for semiconducting vanadium pentoxide. The calculations are based on density-functional theory within the local-density approximation and employ the augmented spherical wave method in its scalar-relativistic implementation. The electronic properties…
This paper presents research results on the electro–thermomechanical behavior of piezoelectric ceramics for use in actuator applications with an emphasis on ferroelectric fatigue. The material being investigated is a lead zirconate titanate piezoelectric ceramic with the composition PbZr0.53Ti0.47O3 (PZT-5H). Results…
The behavior of the phase transitions is mapped out as a function of the dihedral angle (\ensuremath{\theta}) or the transfer integral $(t)$ between donor columns for \ensuremath{\theta}-type BEDT-TTF [BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene, abbreviated as ET] salts involving the series $\ensuremath{\theta}\e…