Materials Literature
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The hydrothermal transformation at 90−95 °C of a slurry of Al 2 O 3 /MgO/(CH 3 COOH)/H 2 O with molar oxide composition 1:4.4:2.2:1111 produced a hydrotalcite-like (HT) material free from phase impurities and having an approximate unit cell composition of Mg 0.66 Al 0.33 (OH) 2 (CHCOO) 0.33 . 13 C NMR and 27 Al NMR sp…
The synthesis and magnetic properties are reported of two new clusters [Mn(10)O(4)(OH)(2)(O(2)CMe)(8)(hmp)(8)](ClO(4))(4) (1) and [Mn(7)(OH)(3)(hmp)(9)Cl(3)](Cl)(ClO(4)) (2). Complex 1 was prepared by treatment of [Mn(3)O(O(2)CMe)(6)(py)(3)](ClO(4)) with 2-(hydroxymethyl)pyridine (hmpH) in CH(2)Cl(2), whereas 2 was ob…
A new family of spin crossover complexes, [Fe(II)H(3)L(Me)](NO(3))(2).1.5H(2)O (1), [Fe(III)L(Me)].3.5H(2)O (2), [Fe(II)H(3)L(Me)][Fe(II)L(Me)]NO(3) (3), and [Fe(II)H(3)L(Me)][Fe(III)L(Me)](NO(3))(2) (4), has been synthesized and characterized, where H(3)L(Me) denotes a hexadentate N(6) tripod ligand containing three…
The development of surface-enhanced Raman scattering (SERS)-active substrates for cancer gene detection is described. The detection method uses Raman active dye-labeled DNA gene probes, self-assembled monolayers, and nanostructured metallic substrates as SERS-active platforms. The mercaptohexane-labeled single-strande…
In a Comment (cond-mat/0310030) on our recent paper on network glasses (Phys. Rev. Lett., 2003, 90, 085505), Micoulaut and Boolchand (MB) compare our predictions on glass transitions in network systems for the ratios of the transition temperatures TA/TG and TK/TG with experimental data. They claim significant differen…
The crystal structure of the α-form of poly( l -lactide) was analyzed by the linked-atom least-squares refinements for the X-ray fiber diffraction data. The space group was orthorhombic P 2 1 2 1 2 1, and the unit cell contained the antiparallel two chains. The chain conformation was the 2-fold s(15*2/7) helix distort…
Carbon nanotubes (CNT) have recently emerged as a promising class of electron field emitters. They have a low threshold electric field for emission and a high emission current density which make them attractive for technological applications. In this article we review recent progress on understanding of CNT field emit…
Mechanical properties of carbon nanotubes are discussed based on recent advances in both modeling and experiment.
Low-temperature excitation has been investigated for polycrystals of ordered double-perovskite alloys ${\mathrm{Sr}}_{2}\mathrm{Fe}({\mathrm{Mo}}_{1\ensuremath{-}y}{\mathrm{W}}_{y}){\mathrm{O}}_{6}$ $(0<~y<~1)$ by specific-heat measurements. Critical enhancement of excess low-temperature specific heat with anoma…
La 0.67 Sr 0.33 MnO 3 ( LSMO ) thin films were grown onto CaMnO3(CMO) buffered SrTiO3(100) by pulsed laser deposition. Because of the in-plane compressive strain induced by the lattice mismatch between CMO and LSMO, a perpendicular magnetic anisotropy (PMA) was obtained in the overlayer LSMO. Using the magnetic force…
The local structure of LiB3O5 single crystal was investigated with Li7 (I=3/2) nuclear magnetic resonance measurements. We observed four different spectra, which could be divided into two groups corresponding to two kinds of lithium atoms, LiA and LiB, lying at crystallographically equivalent sites and magnetically in…
Measurements of the photoluminescence (PL) and photocurrent (PC) have been made on GaSe with excess Ga or Se atoms. The 1.77 eV emission band for the sample with excess Ga atoms is attributed to the transition from the donor level at 0.175 eV to the acceptor level at 0.152 eV. This donor level is considered to be rela…
“Rounding” effects and other specific changes of liquid sulfur’s polymerization transition are studied using Raman scattering in the case of fluid’s spatial confinement in nanonoporous sol-gel glasses. Specifically, in this paper we demonstrate the smearing or “rounding” of the monomer↔polymer transition caused by geo…
The structural and electrical properties of Pb(Zr0.35Ti0.65)O3 (PZT) thin films ranging in thickness from 700 to 4000 Å have been investigated. These (001)/(100)-textured films were grown by metalorganic chemical vapor deposition on (111)-textured Ir bottom electrodes. It was observed that, in the as-deposited state,…
We performed studies on the capillary condensation of various substances in optically anisotropic porous silicon layers. Their strong in-plane form birefringence has been utilized to analyze the polarization state of the transmitted light when molecules penetrate into the pores. The polarization state of the transmitt…
The origin of dramatic variation in optical polarizabilities of push–pull conjugated chains with respect to the conjugation length is discussed. Ab initio calculations of intramolecular charge transfer (ICT)-driven dipole moment (μCT), polarizability (αCT), and first hyperpolarizability (βCT) show that the values of α…
Absorption spectra of Er3+ and Yb3+ ions, codopants in a phosphate glass, are reported at 8 K and at wavelengths between 350 and 1600 nm. Detailed structure appearing in the spectra, associated with individual multiplet states, LJ2S+1, of Er3+(4f11) and Yb3+(4f13) is interpreted using a ligand-field coordination spher…
n- and p-type AlxGa1−xN (x=0.38 for n-type, x=0.13 for p-type) layers grown on Al2O3 substrates were ion implanted with the transition metals Mn, Cr, and Co at high concentrations (peak doping levels ∼3 at. %). After implantation and annealing at 1000 °C, only impurity transitions at ∼2.9 and 3.9 eV and no band-edge p…
Beam fanning has been studied in the cerium-doped ferroelectric relaxor strontium–barium–niobate (Sr0.61Ba0.39Nb2O6:Ce, SBN:Ce) under the application of high external electric fields. Spatial reversal in the distribution of the scattered light is achieved both below and above the phase transition. It is shown that the…
Fictive temperature dependence of density fluctuation in SiO2 glass was investigated by the small-angle x-ray scattering measurement. The density fluctuation in SiO2 glass varies linearly to the fictive temperature. Contribution of structural relaxation to the density fluctuation is larger than that of phonons. Isothe…