Materials Literature
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We present measurements of the magnetic susceptibility and of the thermal expansion of a ${\mathrm{LaCoO}}_{3}$ single crystal. Both quantities show a strongly anomalous temperature dependence. Our data are consistently described in terms of a spin-state transition of the ${\mathrm{Co}}^{3+}$ ions with increasing temp…
Amorphous B−C−N ceramics were produced by thermolysis of poly(borosesquicarbodiimide) of idealized formula [B 2 (NCN) 3 ] n at 1100 °C in an argon atmosphere. Their structure was investigated by X-ray and neutron diffraction. Wide-angle diffraction showed that the ceramics consist of an amorphous structure with hexago…
Semiempirical Hartree-Fock techniques are widely used to study properties of long ring-structured chains, although these types of systems were not included in the original parametrization ensembles. These techniques are very useful for an ample class of studies, and their predictive power should be tested. We present…
A generalized Ginzburg-Landau-Devonshire free energy has been used to describe the influence of imperfect surface layers or interface layers in ferroelectric thin films. The natural boundary condition has been employed in solving the polarization profile, which can reflect a more realistic situation compared to the pr…
The IR spectra of O3 adsorbed on polycrystalline (high surface area) MgO are reported and assigned. Two distinct groups of absorptions in the 1160–970 and 1730–1170 cm−1 spectral regions were observed. The bands falling in the first region, fully reversible upon decreasing the O3 pressure, are grouped into two doublet…
Three aspects of the esterification reaction of silica surfaces with alcohols that are relevant for the synthesis of functional materials have been studied: surface coverage, hydrolytic stability, and the introduction of functional groups. The chemisorption of alcohols on silica can be described by the Langmuir adsorp…
We have investigated the adsorption, decomposition and oxidation of methanol on a well-defined supported Pd model catalyst, utilizing a combination of molecular beam methods, reflection absorption IR spectroscopy (RAIRS) and temperature-programmed desorption (TPD). The Pd model catalyst is prepared under ultrahigh-vac…
Core-shell ensembles of citrate-stabilized gold nanoparticles (20-80 nm) on submicron silica cores (330-550 nm) have been prepared by electrostatic self-assembly with shell packing densities as high as phi = 0.55.
Abstract A new triphenylamine‐containing aromatic diamine, N , N ′‐bis(4‐aminophenyl)‐ N , N ′‐diphenyl‐1,4‐phenylenediamine, was prepared by the condensation of N , N ′‐diphenyl‐1,4‐phenylenediamine with 4‐fluoronitrobenzene, followed by catalytic reduction. A series of novel aromatic polyamides with triphenylamine u…
The synthesis of a series of polymeric Eu(III) complexes with polyester ligands, along with supporting emission spectra, luminescence lifetimes, and, for a Eu block copolymer film, atomic force microscopy (AFM) data, is presented. Dibenzoylmethane was derivatized with a hydroxyl initiator site (dbmOH, 1) for tin octoa…
This paper reports a computational method, the quantized elastic deformational model, that can reliably describe the conformational flexibility of a protein in the absence of the amino acid sequence and atomic coordinates. The essence of this method lies in the fact that, in modeling the functionally important conform…
Superconducting MgB2 thin films were prepared on 50-micrometer-thick, flexible polyamide Kapton-E foils by vacuum co-deposition of Mg and B precursors with nominal thickness of about 100 nm and a special ex-situ rapid annealing process in an Ar or vacuum atmosphere. In the optimal annealing process, the Mg-B films wer…
The superconductivities of samples prepared by several procedures were found to degrade under ambient environment. The degradation mechanism was studied by measuring the change of surface chemical composition of dense MgB2 pellets (prepared by hot isostatic pressure, HIPed) under atmospheric exposure using X-ray Photo…
Polarization hysteresis loops, x-ray diffraction (XRD) and temperature dependent dielectric constant under different electric fields for <110> oriented 0.7 Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystals were measured. The field-induced phase transition and the process of depolarization were discussed. The results show tha…
Coarsening in foams made from the pure liquid crystal, 8CB, has been studied. The foam was made in the nematic phase ($\textrm{T} = 35 ^{\circ}\textrm{C}$) by bubbling nitrogen through the pure liquid crystal. The coarsening behavior was investigated at three temperatures; at $\textrm{T} = 22 ^{\circ}\textrm{C}$ and $…
The novel SnO diskettes have been synthesized by evaporating either SnO or SnO(2) powders at elevated temperature. Disregard the source material being SnO or SnO(2), the SnO diskettes are formed at a low-temperature region of 200-400 degrees C. Two types of diskette shapes have been identified: the solid-wheel shape w…
Bagasse was converted into a thermo-moldable material by cyanoethylation. The effect of reaction conditions employed during the preparation of cyanoethylated bagasse (CE-B) fibers on dielectric properties of hot-pressed composites was studied. Increase in the nitrogen content of the cyanoethylated fiber, i.e., the nit…
Plant fibers are of increasing interest for use in composite materials. They are renewable resources and waste management is easier than with glass fibers. In the present study, longitudinal stiffness and strength as well as morphology of unidirectional sisal–epoxy composites manufactured by resin transfer molding (RT…
The geometries and electronic properties of small lithium-rich ${\mathrm{Al}}_{N}{\mathrm{Li}}_{5N}$ $(N=1--6,10)$ clusters are studied using first-principles simulations. Aluminum ions form a compact inner core configuration in the clusters that changes into a chainlike skeleton embedded in a lithium surrounding as t…
Poly(ester-urethane-imide)s were prepared by Diels–Alder polyaddition of 1,6-hexamethylene-bis(2-furanylmethylcarbamate) with various bismaleimides containing ester groups in the backbone. The Diels–Alder reaction was carried out in m-cresol, at 110°C, followed by thermal and chemical aromatization of tetrahydrophthal…