Materials Literature
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The inherent chromonic lyotropic liquid crystalline properties of a dye have been manipulated to fabricate multi-axial micropolarizing thin films by means of the photoalignment technique. The dye aqueous solution is deposited on a photopatterned polymer film to result in the macroscopic alignment of the dye molecules,…
Abstract A novel, fluorinated diamine monomer with the ether–ketone group, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone ( 2 ), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 4,4′‐dihydroxybenzophenone in the presence of potassium carbonate, followed by cat…
Layered double hydroxides (LDHs, or hydrotalcites) with Mg(2+) and Al(3+) cations in the mixed metal hydroxide layer and paratungstate anions in the interlayer have been prepared. Different methods have been followed: anion exchange with Mg,Al LDHs originally containing nitrate or adipate, reconstruction of the LDH st…
The crystal and magnetic structure of strontium ferrite Sr 4 Fe 4 O 11 (SrFeO 2.75 ) has been investigated using neutron powder diffraction and magnetic susceptibility measurements over the temperature range 1.5–293 K and by Mössbauer spectroscopy at room temperature. Sr 4 Fe 4 O 11 is orthorhombic (symmetry group Cmm…
A high‐quality (0001)‐oriented ZnO layer that emits ultraviolet light at room‐temperature has been prepared by electrodeposition on a (111) Au/(100) Si substrate. The ZnO layer emits ultraviolet light at a photon energy of around 3.3 eV due to the recombination of bound excitons and visible light at 2.34–2.8 eV at roo…
Pristine arc-produced multi-walled carbon nanotubes are contacted to liquid mercury in situ in a transmission electron microscope. The conductance G ( V ) for all tubes increases with increasing bias voltage V . This is related to the electronic density of the nanotubes. Similar G ( V ) behaviour is observed for HOPG-…
We report on a molecular dynamics study of the cross-plane lattice thermal conductivity in GaAs/AlAs superlattices. The layers of the superlattice are modelled by a three-dimensional face centred cubic lattice with cubic anharmonicity, and with atomic scale roughness at the interfaces. We perform the simulation of hea…
A study of crystal structure, elastic, and magnetic properties of low-doped Nd 1− x Ca x MnO 3 ( ) perovskites has been carried out. The ferromagnetic component is shown to increase under hole doping and, simultaneously, the temperature of the orbital order–disorder phase transition decreases. The mechanism of the con…
The infrared spectra of the metcars ${X}_{8}{\mathrm{C}}_{12}$ with $X=\mathrm{V},$ Nb, Zr, in the gas phase, recently determined experimentally using the infrared resonance enhanced multiphoton ionization technique, are computed from first-principles for several of the lowest-energy local minima found for these clust…
Binding of a poly(amido amine) dendrimer with salmon testes DNA in an aqueous solution of 0.01 M NaCl at pH 6.5 has been investigated. It was shown from the physicochemical experiments of static light scattering and ultra-violet and circular dichroism spectroscopy that at a 0.2 mixing ratio of dendrimer/DNA (number ra…
Effects of organic additives, such as benzoic acid (BA) and poly(ethylene glycol)s (PEGs), on the initial stage of the zinc electrodeposition have been investigated at iron electrodes using cyclic voltammetry, electrochemical quartz crystal microbalance measurements and in situ electrochemical scanning tunneling micro…
Abstract The formulation and finite element implementation of a finite deformation continuum theory for the mechanics of crystalline sheets is described. This theory generalizes standard crystal elasticity to curved monolayer lattices by means of the exponential Cauchy–Born rule. The constitutive model for a two‐dimen…
An expansion method for perturbation of the zero temperature grand canonical density matrix is introduced. The method achieves quadratically convergent recursions that yield the response of the zero temperature density matrix upon variation of the Hamiltonian. The technique allows treatment of embedded quantum subsyst…
In recent years, disorder has been shown to be crucial for the understanding of diluted magnetic semiconductors. Effects of disorder in these materials are reviewed with the emphasis on theoretical works. The types and spatial distribution of defects are discussed. The effect of disorder on the intimately related tran…
Structure, transport and magnetic properties have been investigated for layered NaCo1-xMnxO2 materials. With the increase of Mn-doping amount, measurements of x-ray diffraction indicate that the in-plane lattice parameter a decreases progressively, and, conversely, the lattice parameter c increases rapidly. Small amou…
The use of ultrafast gating techniques allows us to resolve both spectrally and temporally the emission from short-lived neutral and negatively charged biexcitons in ultrasmall (sub-10 nm) CdSe nanocrystals (nanocrystal quantum dots). Because of ``forced'' overlap of electronic wave functions and reduced dielectric sc…
A review of double resonance Raman spectroscopy is presented. Non-zone centre phonon modes in solids can be observed in the double resonance Raman spectra, in which weak Raman signals appear in a wide frequency region and their combination or overtone modes can be assigned. By changing the excitation laser energy, we…
We report several wet-chemical methods for synthesis of one-dimensional CuO nanostructures in water−ethanol mixed solvents at 77−82 °C and 1 atm. Single-crystalline monodispersed CuO nanorods with a selected breadth in the range of 5−15 nm have been prepared by controlling reagent concentrations. The nanorods are pref…
The effect of free surfaces on the glass transition temperature (T(g)) of thin polystyrene films was studied. Measurements were performed on films (8 nm<h<290 nm) with one free surface and on films capped with a 5 nm thick metal layer (no free surfaces). Potential problems with evaporative deposition were eliminated b…
Abstract Functional hybrids are nanocomposite materials lying at the interface of organic and inorganic realms, whose high versatility offers a wide range of possibilities to elaborate tailor‐made materials in terms of chemical and physical properties. Because they present several advantages for designing materials fo…