Materials Literature
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Irreversible adsorption of hard spheres at random site surfaces was studied theoretically. In contrast to the previous model of Jin et al. [J. Phys. Chem. 97, 4256 (1993)] the dimension of the sites, having the shape of circular disks, was finite and comparable with the size of adsorbing spheres. Adsorption was assume…
As a part of a broader study directed towards helical coordination compounds with benzenedithiolate donors, we have synthesized the bis(benzenedithiol) ligands 1,2-bis(2,3-dimercaptobenzamido)ethane (H(4)-1) and 1,2-bis(2,3-dimercaptophenyl)ethane (H(4)-2). Both ligands form dinuclear complexes with Ni(II), Ni(III) an…
A comprehensive presentation of the temperature evolution of "linear" and "nonlinear" dielectric relaxation in the isotropic phase of nematic liquid crystalline compound 5CB (4-cyano-4-n-pentylbiphenyl) is given. The "nonlinear" relaxation is related to the strong pretransitional rise in the lifetime of prenematic flu…
Domain configuration and ferroelectric related properties of Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 were investigated as a function of applied electric field for the (110) cub cuts. It was found that a single domain orthorhombic state could be achieved by applying an electric field along the direction <110> cub , but the stat…
The preparation of the thiol-derivatised iron(II) phthalocyanine (FePc) complex, 2,3,9,10,16,17,23,24-octabutylthiophthalocyaninatoiron(II), FePc(SC4H9)8, is described. Electrochemical data obtained by both cyclic voltammetry and Osteryoung square wave voltammetry in DMF showed four redox couples. Kinetics and equilib…
Chemical vapor deposition (CVD) has been used to grow sulfur doped diamond films on undoped Si and single crystal HPHT diamond as substrates, using a 1% CH4/H2 gas mixture with various levels of H2S addition (100–5000 ppm), using both microwave (MW) plasma enhanced CVD and hot filament (HF) CVD. The two deposition tec…
A new layered strontium cobaltite, Sr x CoO 2 , was synthesized by a low-temperature ion-exchange technique from a γ-Na 0.7 CoO 2 precursor. The strontium content was determined to be x = 0.345 by inductively coupled plasma (ICP) analysis. Rietveld analysis of X-ray powder diffraction data indicates that strontium ion…
Domain structures of unpoled as well as poled (along [001]- and [110]-direction) Pb(Zn1/3Nb2/3)O3 (PZN)-8% PbTiO3 (PT) and Pb(Mg1/3Nb2/3)O3 (PMN)-29% PT single crystals have been investigated by scanning force microscopy (SFM) in the piezoresponse mode, at room temperature. Antiparallel domain structures have been det…
A study was made to investigate an optimum condition for ruthenium tetraoxide staining of poly(butylene terephthalate) (PBT) with glass transition temperature as low as ca. 23 degrees C for TEM observation of melt-grown PBT crystals. The morphological study of ultrathin sections prepared based on optimum staining at 2…
Successful fabrication of epitaxial thin films of La 2- x Sr x NiO 4 (0.5≤ x ≤1.4) has enabled us to investigate the change in charge dynamics upon the insulator–metal transition (IMT). The charge gap induced by (π,π) charge ordering as observed in optical spectra for x =0.5 is decreased with the increase of x , while…
Zwischen nahem UV und Grün lässt sich die Emission von Nanopartikeln von 1,3-Diphenyl-5-pyrenyl-2-pyrazolin (DPP; siehe Bild) abstimmen, wobei die Farbe des Lichts durch die Anregungswellenlänge und durch die Partikelgröße beeinflusst wird. In Lösung beobachtet man dagegen nur die Emissionscharakteristiken des Pyren-,…
The resonance-type energy transfer process has been investigated for the first time in Ce and Eu co-doped CaGa 2 S 4 polycrystalline samples with different dopant concentrations in the range from 0.2 at.% to 4 at.%. The energy transfer from Ce to Eu ions increases with increasing Ce and Eu concentrations. The values o…
A quantitative analysis of the (2×1) reconstruction of the diamond (111) surface by low-energy electron diffraction (LEED) is presented. Spot intensity versus energy data, I (E), were collected for normal incidence up to electron energies of 500 eV and analysed using the tensor LEED perturbation method. A close fit be…
Relaxation modes and rates of a polymer chain in a melt are studied by Monte Carlo simulations of the bond fluctuation model, where only the excluded volume interaction is taken into account. Polymer chains, each of which consists of N segments, are located on an L × L × L simple cubic lattice under periodic boundary…
We report on magnetometry, resistivity and Mössbauer spectroscopy measurements on single-phase Fe 3 BO 5 in a wide temperature range from 4.2 to 620 K. Magnetically split Mössbauer spectra were observed below T N = 114 K, although a proportion of the Fe 2+ ions in the basal plane (crystallographic site Fe1) remain par…
Reaction of [(Me3tacn)V(CF3SO3)3] (Me3tacn = N,N',N''-trimethyl-1,4,7-triazacyclononane) with LiCN in DMF results in oligomerization of cyanide to form [(Me3tacn)2V2(CN)4(mu-C4N4)]. The structure of this binuclear complex features a planar tetracyanide unit bridging two VIV centers via imido type linkages. The conjuga…
Several cofacial phthalocyanines (Pcs) with an Si-Si linkage were obtained by one-step condensation of 1H-isoindole-1,3(2H)-diimine with hexachlorodisilane as template in quinoline. They were characterized by gel-permeation chromatography, IR, NMR spectroscopy, and mass spectrometry, and cyclic voltammetry. The result…
Die wohldefinierte Anordnung von Poren und Wänden aus Nanokristalliten in einem mesoporösen Titanoxid-Dünnfilm kann mit hohen Konzentrationen (bis zu 8 Mol-%) von Eu3+ unter Bildung eines rot photolumineszierenden Materials dotiert werden (siehe Bild). Die Photolumineszenz stammt von einem Energietransfer von den Band…
The finite-difference time-domain method has been used in the numerical analysis of the optical diffraction properties of a liquid crystal phase grating. The grating is formed using a nematic material that is switched using striped electrodes with a unity mark-space ratio. Three different surface pretilts have been in…
Radiation damage and recrystallization in natural zircons have been studied by analysing Si-O stretching overtones/combinations, hydrous species, and U-ion spectra in the frequency region between 1200 and 11 000 cm -1 . The effects of radiation are characterized by a dramatic variation of intensity, a decrease in freq…