Materials Literature
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We studied the luminescence properties of Eu 2 + in CaAl 2 Si 2 O 8 . In CaAl 2 Si 2 O 8 : Eu 2 + phosphor, two emission bands were observed. Because the two emission bands of CaAl 2 Si 2 O 8 : Eu 2 + phosphor are quite different, it can be presumed that Eu 2 + ions occupy two types of sites, namely, Eu 1 and Eu 2 . T…
It is well known that rigid dipolar solutes (in smaller quantity) dispersed in a nonpolar glassy matrix exhibit a sub-T(g) (or beta(s)) relaxation due to the solute often designated as Johari-Goldstein (JG) relaxation, which is intermolecular in nature. In this article, we report the results of our study of such a sub…
Abstract Covalently bonded layered silicated/polystyrene nanocomposites were synthesized via atom transfer radical polymerization in the presence of initiator‐modified layered silicate. The resulting nanocomposites had an intercalated and partially exfoliated structure, as confirmed by X‐ray diffraction and transmissi…
Abstract (enH 2 )[{Mn(en) 2 (enH)} 2 (μ‐en)](Ge 2 Se 7 ) 2 ( 1 ) and [Mn(dien) 2 ] 2 Ge 2 Se 7 ( 2 ) can be prepared by solvothermal reaction of elemental Ge and Se with Mn(OOCCH 3 ) 2 ·4H 2 O in respectively superheated ethylenediamine/methanol (3:2 mixture, 150°) and diethylenetriamine (dien, 130 °C). The cyclic Ge…
Thin polystyrene (PS) liquid films supported by oxidized silicon (SiO x /Si) substrates may be unstable or metastable, depending on the film thickness, h . In the metastable thickness regime, holes nucleate throughout the surface of the films and subsequently grow under the action of capillary forces. Recent studies s…
Abstract Properties of injection‐molded biodegradable polyesteramide composites containing 5 and 13 wt% octadecylammonium‐treated montmorillonite clay have been studied. Oxygen transmission rates and mechanical properties were measured. X‐ray diffraction was used to assess the degree of intercalation of the clay layer…
The superelastic/shape-memory material, Nitinol, an approximately equiatomic alloy of Ni and Ti, is rapidly becoming one of the most important metallic implant materials in the biomedical industry, in particular for the manufacture of endovascular stents. As such stents are invariably laser-machined from Nitinol tubes…
The structure of yttrium oxide influences the CO oxidation activity of Au/Y2(O3) catalysts; nanocrystalline Y2(O3) stabilizes more active species of gold and increases the activity of the gold catalyst in comparison with mesostructured and precipitated Y2(O3).
The surface conductance of hydrogen-terminated diamond was investigated under air, HCl, and NH 3 vapors using tungsten point contacts, gold/titanium ohmic contacts, and aluminum rectifying contacts. In all cases the conductance decreased with increasing pH. Upon imposition of a step temperature change, there is a tran…
An azido-bridged chain with formula [Mn(Menic)(N3)2]n, where Menic is methylnicotinate, was prepared and studied from the magnetic point-of-view. This compound crystallizes in the monoclinic system, space group P21/a, with a = 15.556(2), b = 16.831(2), c = 17.595(2) Å, β = 110.80(1)° and Z = 10. The structure consist…
Electric-field-induced transient pore formation (electroporation) in synthetic unilamellar dioleoylphosphatidylcholine vesicles of 178-nm diameter is utilized for the preparation of subnanometer-size PbS quantum dots. With Pb2+ ions originally entrapped in the vesicles and S2- ions placed in the bulk, their reaction i…
The local, temperature dependent structure of poly-(ethylmethacrylate) was studied with wide-angle x-ray scattering. The results were set into context to recent wide-angle neutron scattering results as well as to the results from a multitude of studies of the dynamics of this polymer. The temperature dependence of the…
Owing to the positively charged grain boundary cores in acceptor-doped and oxygen vacancies are depleted in the space charge layers. The validity of this space charge concept was checked for -doped ceramic of high purity. Electrical fields up to were applied to the grain boundaries of 1.0 mol % -doped at 400°C in air,…
Cu-Co bimetallic mixtures with ceria and YSZ have been investigated as solid oxide fuel cell (SOFC) anodes. While pure Co is unstable in dry CH 4 at 1073 K due to severe carbon formation, Cu-Co mixtures with even 90 wt % Co showed only small amounts of carbon following exposure to dry CH 4 for 2 h at 1073 K. Cells bas…
Abstract Ultrasound medical applications, such as an ultrasound imaging with micro‐bubble contrast agents, and high intensity focused ultrasound (HIFU) therapy have attracted much attention in recent years. These applications have a close relation to the motion of micro‐bubbles, so that it is essential to understand t…
An analytical description of polymer melts and their mixtures as liquids of interacting soft colloidal particles is obtained from liquid-state theory. The derived center-of-mass pair correlation functions with no adjustable parameters reproduce those computed from united atom molecular dynamics simulations. The coarse…
We investigate the structures and magnetic properties of small Mn(n) clusters in the size range of 2-13 atoms using first-principles density functional theory. We arrive at the lowest energy structures for clusters in this size range by simultaneously optimizing the cluster geometries, total spins, and relative orient…
Nanostructured ZnFe 2 O 4 and zinc oxide−iron oxide composites were obtained by sol−gel processing of a hetero-bimetallic alkoxide. For this purpose the novel molecular precursors Fe 2 Zn(OR) 8 (R = t Bu, i Pr), fully characterized by spectroscopic and single-crystal diffraction techniques, have been synthesized and t…
This article reviews the most recent progress in the synthesis of polar-surface dominated semiconducting and piezoelectric ZnO nanostructures: including nanosprings, nanohelices, nanorings, nanobows and nanodisks. These structures were formed by self-assembly of polar nanobelts/nanowires as driven by minimizing electr…
Abstract A recently developed method to determine the energy levels of divalent lanthanide ions relative to the conduction band and valence band of host compounds is applied to Sr 2 MgSi 2 O 7 doped with Eu 2+ and Dy 3+ . The level locations are not consistent with the widely adopted and generally believed mechanism o…