Materials Literature
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The perovskite polymorph of YbMnO 3 has been revisited. The orthorhombic phase is obtained through a high-pressure (HP) reconstructive transformation from the hexagonal sol−gel-synthesized YbMnO 3 by means of HP annealing at 5 GPa and 1100 °C. Neutron powder diffraction shows that the HP form crystallizes in the ortho…
Hyperbranched glycopolymers were grafted from a silicon wafer with a covalently attached initiator layer of α-bromoester fragments using self-condensing vinyl copolymerization (SCVCP) of the methacrylic AB* inimer, 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM), and a sugar-carrying methacrylate, 3- O -methacryloyl…
The large scale formation of uniform Sb 2 S 3 nanorod-bundles has been achieved via a simple and mild hydrothermal approach with the assistance of polyvinylpyrrolidone. By closely inspecting the growth process and the crystallographic analysis of as-synthesized products, conclusive evidence has been provided to show t…
The photostability of thiol-capped CdTe quantum dots (QDs) in Euglena gracilis (EG 277) and human embryonic kidney (HEK 293) cells was studied. The photobleaching for the cellular QDs is dependent both on the irradiation power density and the QD local concentration. The photostability of cellular QDs is better than th…
A series of heteroleptic bis(phthalocyaninato) europium(III) complexes, namely, Eu(Pc)[Pc(15C5)] (2), Eu(Pc)[Pc(opp-15C5)2] (3), Eu(Pc)[Pc(adj-15C5)2] (4), Eu(Pc)[Pc(15C5)3] (5), and Eu(Pc)[Pc(15C5)4] (6) [Pc = unsubstituted phthalocyaninate; Pc(15C5) = 2,3-(15-crown-5)phthalocyaninate; Pc(opp-15C5)2 = 2,3,16,17-bis(1…
Gold or Silver nanoparticles have been immobilized on the surface of poly(4-vinylpyridine) fibers and poly(4-vinylpyridine)/poly(methyl methacrylate) composite fibers by in situ synthesis or by self-assembly. Polymer fibers with submicrometer diameters were fabricated using an electrospinning process and modified to i…
Here we demonstrate, for the first time, that it is possible to synthesize a polymer that exhibits no orientational birefringence and no photoelastic birefringence using two methods. In these methods, the contributions of monomers and an anisotropic dopant to orientational birefringence and photoelastic birefringence…
With such a wide diversity of properties and applications, is it any wonder that industry and academia have such a fascination with polymers? A solid introduction to such an enormous and important field is critical to the modern polymer scientist-to-be, but most of the available books do not stress practical problem s…
A photochromic symmetric Schiff base, N,N'-bis(salicylidene)-p-phenylenediamine, is proposed as a probe for the study of solvent dependent enol-keto tautomerism in the ground and excited states. The ground state equilibrium between the enol-keto tautomers is found to depend mainly not on polarity but on the proton don…
Abstract Quantitative temperature‐modulated differential scanning calorimetry (TMDSC) and superfast thin‐film chip calorimetry (SFCC) are applied to poly(butylene terephthalate)s (PBT) of different thermal histories. The data are compared with those of earlier measured heat capacities of semicrystalline PBT by adiabat…
Using the full potential linearized augmented plane wave (FLAPW) method, we have explored the magnetic properties of one dimensional (1D) Ti atomic chain. Astonishingly, we for the first time observed that the 1D Ti atomic chain has ferromagnetic ground state even on NiAl(110) surface although the Ti has no magnetic m…
Recent claims of an experimental demonstration of spontaneous spin polarisation in dilute electron gases \cite{young99} revived long standing theoretical discussions \cite{ceper99,bloch}. In two dimensions, the stabilisation of a ferromagnetic fluid might be hindered by the occurrence of the metal-insulator transition…
We present ab initio calculations of the magnetic susceptibility and of the $^{13}\mathrm{C}$ chemical shift for carbon nanotubes, both isolated and in bundles. These calculations are performed using the recently proposed gauge-including projector augmented-wave approach for the calculation of magnetic response in per…
The high-pressure behavior of ${\mathrm{Ga}}_{2}{\mathrm{O}}_{3}$ is studied up to $40\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ using synchrotron x-ray diffraction and Raman spectroscopy in diamond anvil cells. A phase transformation from the monoclinic $\ensuremath{\beta}$-phase $(C2∕m)$ is observed at a pressure abov…
For a previously published study of the titanium hexagonal close packed $(\ensuremath{\alpha})$ to omega $(\ensuremath{\omega})$ transformation, a tight-binding model was developed for titanium that accurately reproduces the structural energies and electron eigenvalues from all-electron density-functional calculations…
Based on density functional perturbation theory, we have studied the vibrational properties of three crystalline phases of tellurium dioxide: paratellurite $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{TeO}}_{2}$, tellurite $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{TeO}}_{2}$, and the new phase $\ensuremath…
X-ray photoemission spectroscopy has been used to investigate the depth dependent crystal structures and chemical compositions of sequentially chemical-etched YBa2Cu3O7-d (YBCO) ultrathin film superconductors. In the near-interface region the crystal structure is severely oxygen deficient and of tetragonal symmetry. W…
The synthesis, structure, and characterization of a new noncentrosymmetric molybdenum tellurite, Na 2 Te 3 Mo 3 O 16, are reported. Na 2 Te 3 Mo 3 O 16 crystallizes in the noncentrosymmetric monoclinic space group I 2 (No. 5, cell choice 3) with a = 7.3373(10) Å, b = 11.2668(16) Å, c = 8.2369(18) Å, and β = 97.387(3)°…
”Systematic errors”, namely, oxygen vacancy sites in ZnO, are the active centers for the hydrogenation of CO to give methanol. Nanocrystalline ZnO with a high density of oxygen vacancies was prepared from special organometallic precursors, and its catalytic properties for methanol synthesis were studied.
Using in situ high-resolution synchrotron x-ray scattering, the Curie temperature TC has been determined for ultrathin c-axis epitaxial PbTiO3 films on conducting substrates (SrRuO3 on SrTiO3), with surfaces exposed to a controlled vapor environment. The suppression of TC was relatively small, even for the thinnest fi…