Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTAmphiphilic Heteroarm Star-Shaped Polymers by Living Cationic Polymerization: A Unique Behavior in Aqueous Solution 1Shokyoku Kanaoka, Satoru Nakata, and Hitoshi YamaokaView Author Information Department of Materials Science, School…
High thermal stability and high surface area alumina nanoparticles, containing variable amounts of barium, have been prepared by using combined microemulsion and hydrothermal techniques.
Clusters with closed electronic shells are highly stable, and this is a robust property with far-reaching implications for cluster abundance, cluster shapes, dynamical response to electric fields and cluster dissociation. Clusters with closed shells are also good candidates for the synthesis of novel materials. The de…
An accurate structural study on the β-phase of LiNaSO 4 was carried out. This study shows that twin crystals are usually obtained when crystallization takes place from solution, which explains the observed low spontaneous polarization. Raman scattering of Li 2 SO 4 , Na 2 SO 4 and LiNaSO 4 is explained from the struct…
The picosecond dynamics of molten alkali halides is discussed, and the low-frequency Raman spectra of molten LiCl, CsCl, and the LiCl–CsCl eutectic are fitted to the model enabling to obtain the times of vibrational dephasing, τV and vibrational frequency modulation τω. In terms of the Wilmshurst criterion [J. Chem. P…
The octanuclear aggregates M(8)(mu(4)-O)(2)(O(2)CN(i)()Pr(2))(12) [M = Mn(II) 1, Co(II) 2, Ni(II) 3] have been prepared in good yields by controlled hydrolysis of the corresponding metal carbamate precursors [M(O(2)CN(i)()Pr(2))(2)](n)(). X-ray analysis has shown compounds 1-3 to be isostructural. The core of 2 contai…
Amide routes starting from either Ta(NMe2)5 or (C2B9H11)Ta(NMe2)3 have been employed to synthesize the first tantalasilsesquioxanes including the “half-sandwich” complex Cy7Si7O12Ta(NMe2)2 (3, Cy = c-C6H11), the anionic “sandwich” complex [H2NMe2][Ta(Cy7Si7O12)2] (4) as well as the novel “mixed-sandwich” complex Cy7Si…
The room temperature excitation spectrum of luminescence of Cr 3+ in the YAl 3 (BO 3 ) 4 single crystal have been used to estimate the crystal-field strength Dq and the Racah parameters B and C . The Dq / B = 2.4 value indicates that dopant ions occupy strong-crystal-field sites. Emission spectra of Cr 3+ are consiste…
We report room-temperature Raman scattering results on perovskite-type [(La 0.7 Sr 0.3 MnO 3 ) m /(SrTiO 3 ) n ] 15 multilayers, m and n being the thicknesses of layers alternated 15 times. Distinct changes in the Raman spectra for different n and m have been analysed in the light of structural modifications and point…
High-density amorphous ice (HDA), made by compression of hexagonal ice at 77 K, was heated at a constant pressure of 0.81 GPa up to 195 K and its phase transition followed by displacement-temperature curves. The crystalline phases recovered at 77 K and 1 bar were characterized by X-ray diffraction. Pure D 2 O ice IV a…
The effect of nonmesogenic solute on the nematic-smectic-A (NA) transition is examined within the Landau phenomenological theory. When nonmesogenic solute are added to a mesogenic compound consisting of both nematic and smectic-A phases, the NA transition temperature is depressed and a two phase region is formed due t…
The discovery of a new monoclinic phase in the PbZr 1- x Ti x O 3 (PZT) system in the vicinity of the morphotropic phase boundary (MPB), previously considered as a region where the rhombohedral and tetragonal phases of PZT coexist, was recently reported. Investigations of this new phase were reported using different t…
Abstract Twenty‐nine new photochromic 2,4,7‐substituted fluorene‐9′‐styrylquinolinedihydroindolizines (DHIs) 4a–χ were prepared in 45–75% yield via nucleophilic addition of 4‐styrylquinolines 2a–k to substituted spirocyclopropenes 1a–c . The absorption maxima (λ max ) of the colored betaines 3a–χ were detected by flas…
Covalent linkage of oleic acid ligated Fe3O4 spheres (9 nm) with sheetlike [H1-xCa2Nb3O10] particles (300 x 300 x 2 nm) yields, depending on conditions, submicro- or microscale stacks, which on their surfaces are decorated with magnetite nanoparticles. Due to the optical anisotropy of the sheetlike Ca2Nb3O10 building…
The effect of the microstructure of tin-doped indium oxide (ITO) films on their electrochemical performance was studied using three redox probes, tris(2,2'-bipyridyl ruthenium(II) chloride (Ru(bpy)3(2+/3+)), ferrocyanide (Fe(CN)6(4-/3-)), and ferrocenemethanol (FcCH2H(0/+)). ITO films were deposited using dc magnetron…
Theoretical descriptions of the molecular nonlinear optical properties of tetrahedral donor–acceptor molecules are presented by using a valence-bond and four charge-transfer state model. Based on this five-state model, as the extent of the charge transfer from the peripheral donors (acceptors) to the central acceptor…
Silica-supported cobalt catalysts, Co/SiO2, were prepared by the saturating chemisorption of gaseous cobalt acetylacetonate reactants, Co(acac)2 and Co(acac)3. Thermoanalytical investigation indicated that both reactants are suitable for the preparation of cobalt catalysts in the temperature range 170–220 °C. Co(acac)…
The iron-containing cores of ferritin were used as catalyst for the growth of patterned films of multiwall carbon nanotubes by chemical vapor deposition of C 2 H 2 at 720 °C. The catalyst was delivered onto SiO 2 /Si substrates by microcontact printing and onto SiO/Cu transmission electron microscopy grids by dipping.…
Thin films of tungsten oxide were deposited onto silicon substrates using reactive rf sputtering. The structure of the films is strongly dependent on the conditions of deposition and post-treatment. Important issues are the influences of oxygen pressure during deposition and of annealing temperature. We used x-ray pho…
Raman spectroscopy is applied in this work to study the adsorption of poly(ethyleneimine) (PEI) on Ag nanoparticles obtained by reduction with citrate, as well as to the study of the interaction between PEI and a plasmid. The surface-enhanced Raman spectroscopy (SERS) affords important information about the interactio…