Materials Literature
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Three unsubstituted cyclic ketene acetals (CKAs), 2-methylene-1,3-dioxolane, 1a, 2-methylene-1,3-dioxane, 2a, and 2-methylene-1,3-dioxepane, 3a, undergo exclusive 1,2-addition polymerization at low temperatures, and only poly(CKAs) are obtained. At higher temperatures, ring-opening polymerization (ROP) can be dominant…
Low-voltage scanning electron microscopy (LV-SEM) was used to monitor contamination by carbonaceous compounds on the surface of two different commercially available titanium dental implants. Because of its higher surface sensitivity, the LV mode allows us to image contaminating materials on surfaces that are undetecte…
A series of neutral and cationic Ni(II) and Pd(II) complexes with the open tetraaza ligand bisoxazoline bisamine N 4, were prepared and characterized. Neutral complexes presented dimeric structures of stoichiometry [M 2 (μ-N 4 )X 4 ] (M = Ni ( 1 ), Pd ( 2 )) and underwent slow decomplexation in coordinating solvents.…
During 3 years that have passed since MEIPIC-2 conference investigations have been conducted in the field of expanding and ascertaing data obtained in physics and technique of magnetoelectric phenomena. Below is a brief review of papers presented to MEIPIC-3 conference.
The infrared and Raman spectra of tetracalcium phosphate (Ca4P2O9) were measured and interpreted on the basis of factor group analysis. Factor group splitting can be noted for the various internal vibrational modes of the PO4 3- ion. However, a fewer number of factor group-split bands can be seen than predicted becaus…
Isostructural HfGeO 4 and ZrGeO 4, activated with Ti 4+, yield blue luminescence when irradiated with X-rays. An adequate understanding of the observed blue luminescence requires the determination of the site occupancy and the local Ti 4+ environment; i.e., the site symmetry. Raman spectroscopy has been used to probe…
The toolbox for spin coupling is now well equipped, since nearly all possible topologies of organic tri- and tetraradicals are known, which can be applied as building blocks for the synthesis of practically useful polyradical materials. High-spin polyradicals could be useful as organic ferromagnets, whereas several lo…
A series of single crystals of quasi-one-dimensional halogen-bridged Ni-Pd mixed-metal compounds, Ni<SUB>1-x</SUB>Pd<SUB>x</SUB>(chxn)<SUB>2</SUB>B<SUB>r3</SUB> (chxn equals 1R, 2R- cyclohexanediamine) have been obtained by electrochemical oxidation methods. In order to investigate the competition between the electron…
Using the previously reported vibrational results (infrared, Raman and resonance Raman spectra) for the Ce2O2S and Ce2.0O2.5S solid compounds (see Part I), comparative lattice dynamics calculations were performed. These calculations allow one to reproduce satisfactorily the experimental wavenumbers and to propose more…
Abstract Vinylformamide (VFA) is cationically polymerized in various solvents at 273 K and reaction temperature by the following initiators: iodine, bis(4‐methoxyphenyl)‐methyl chloride/silica, triphenylmethyl chloride/silica, and trimethylsilyl triflate. In every case defined oligomers with narrow molecular weight di…
We present an x-ray diffuse scattering study of the anion ordering (AO) transition in the ${(\mathrm{TMTSF})}_{2}{(\mathrm{R}\mathrm{e}\mathrm{O}}_{4}{)}_{1\ensuremath{-}x}({\mathrm{ClO}}_{4}{)}_{x}$ solid solution of quasi-one-dimensional organic conductors and superconductors. As ${(\mathrm{TMTSF})}_{2}{\mathrm{ReO}…
A detailed study of the magnetic behavior of the molecule-based magnet, [MnOEP][HCBD], (OEP=meso-octaethylporphyrinato, HCBD=hexacyanobutadiene) from 1.7 to 20 K was performed. The earlier reported magnetic transition at 19.6 K, ascribed to a crossover from a one-dimensional Heisenberg-like ferrimagnet to a two-dimens…
Abstract The interaction between the oppositely charged polymers poly(diallyldimethylammonium chloride) (PDADMAC) and poly(maleic acid‐co‐α‐methylstyrene) (P(MAMS)) in the presence of cellulose can be used for strong surface modification. The dependence of the modification effect on the concentration of polymers and o…
Oxygen tracer diffusion in polycrystalline (La,Ca)CrO 3−delta was studied by the gas‐solid isotope exchange reaction in combination with a depth‐profiling technique using secondary‐ion mass spectroscopy, which allowed determination of coefficients of lattice and grain‐boundary diffusion separately. A significant contr…
The first study of materials based on ultradisperse diamond produced by detonation is reported. A luminescence band in the visible has been observed, and some of its structural features have been interpreted by analogy with the known luminescence bands of centers in synthetic and natural diamonds. A comparison of the…
A contact preparation is made between a cholesteric photocrosslinkable material and a standard nematic liquid crystal. The concentration and the anisotropy progressively and homogeneously vary along a direction perpendicular to the diffusion front. On the basis of scanning electron microscopy investigations, compariso…
The magnetoelectric effect of rare earth manganese oxides RMn2O5 (R = Eu, Gd, Tb, Ho, Er, Yb and Y) has been studied by a quasistatic magnetoelectric method for the purpose of determining whether linear magnetoelectric effect is present or not. The results indicate that the main part of the effect at 4.2 K is represen…
Abstract Emission Mössbauer spectra of the title compound measured below 80 K consist of three components ascribed to two Fe(II) high-spin states and one Fe(III) low-spin state. It was concluded that a part of the Fe(II) high-spin species converts to an Fe(III) high-spin species above 210 K, based on the comparison of…
The symmetry of current–voltage ( I–V ) characteristic of the metal–insulator–metal (MIM) element with the insulator of tantalum anodic oxidation TaO x which is heat-treated in hydrogen (hydrogen-treated) is greatly improved. Meanwhile, the symmetric I–V characteristic, unlike that of the conventional MIM element with…
Abstract Die Temperaturabhängigkeit der Zersetzungsdrücke der auf dem quasibinären Schnitt Bi 2 O 3 /BiI 3 existierenden ternären Verbindungen wurde durch Gesamtdruckmessungen mit dem Membrannullmanometer und dem Massenspektrometer ermittelt. Das Zustandsbarogramm für das System wurde aufgestellt und das Zustandsdiagr…