Materials Literature
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The construction of the multi-focal Veselago lens predicted earlier is proposed on the basis of a uniaxial photonic crystal consisting of cylindrical air holes in silicon that make a triangular lattice in a plane perpendicular to the axis of the crystal. The object and image are in air. The period of the crystal shoul…
Excitation of plasmons in a metal nanoparticle leads to localization of electromagnetic fields within the particle, which is expected to result in strong optical nonlinearities. We study ultrafast nonlinearities in optical scattering from single gold nanorods under resonant excitation at the plasmon frequency, and obs…
Time-resolved magneto-optical Kerr spectroscopy of ferromagnetic InMnAs reveals two distinct {\em demagnetization} processes -- fast ($<1$ ps) and slow ($\sim$100 ps). Both components diminish with increasing temperature and are absent above the Curie temperature. The fast component rapidly grows with pump power and s…
We propose a computationally efficient approach to multiscale simulation of polycrystalline materials, based on the phase field crystal model. The order parameter describing the density profile at the nanoscale is reconstructed from its slowly varying amplitude and phase, which satisfy rotationally covariant equations…
Equilibrium crystal structures for ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}\mathrm{Mn}{\mathrm{O}}_{3}$ have been calculated using hybrid Hartree-Fock and density functional methods. Two distinct ground states with either conventional checkerboard charge ordering, in which Mn ions have formal valence 3 or 4, or Zener p…
Mechanical relaxation behaviour of various natural volcanic glasses have been investigated in the temperature range RT-1200K using special low frequency flexure (f~0.63Hz) pendulum experiments. The rheological properties complex Young's modulus M* and internal friction 1/Q have been studied from a pure elastic solid a…
We show that separating metallic from semiconducting carbon nanotubes by dielectrophoresis is developing towards a bulk separation method, which allows for the first time to produce thin films of only metallic single-walled carbon nanotubes and to measure their optical absorption spectra. The data proofs that the sele…
Multiferroic rare earth manganites attracted recent attention because of the coexistence of different types of magnetic and ferroelectric orders resulting in complex phase diagrams and a wealth of physical phenomena. The coupling and mutual interference of the different orders and the large magnetoelectric effect obse…
A new interpretation of the optical and energy-loss spectra of hexagonal boron nitride is provided based on first-principle calculations. We show that both spectra cannot be explained by independent-particle transitions but are strongly dominated by excitonic effects. The lowest direct and indirect gaps are much large…
Thermophilic organisms flourish in varied high-temperature environmental niches that are deadly to other organisms. Recently, genomic evidence has implicated a critical role for disulfide bonds in the structural stabilization of intracellular proteins from certain of these organisms, contrary to the conventional view…
The $\ensuremath{\pi}$-stacking interaction between various planar organic molecules is investigated within the framework of ab initio calculations. The adsorption of these molecules on the sidewall of the cylindrical carbon structure induces a small binding energy compared to conventional covalent functionalization.…
A convenient process for generating large-scale, horizontally aligned arrays of pristine, single-walled carbon nanotubes (SWNTs) is described. The approach uses guided growth, by chemical vapor deposition (CVD), of SWNTs on miscut single-crystal quartz substrates. Studies of the growth reveal important relationships b…
White light was generated from a single silica thin film made with Yb0.75La0.2Eu0.05F3, La0.45Yb0.5Er0.05F3, and La0.75Yb0.2Tm0.05F3 nanoparticles by exciting with a single source near-infrared light (980 nm CW diode laser). Eu3+ and Tm3+ ions are responsible for red and blue emission, respectively. Er3+ ion is respon…
Individual carbon nanotubes are like minute bits of string, and many trillions of these invisible strings must be assembled to make useful macroscopic articles. We demonstrated such assembly at rates above 7 meters per minute by cooperatively rotating carbon nanotubes in vertically oriented nanotube arrays (forests) a…
Rb2[AuII2][AuIIII4], dirubidium diiodoaurate(I) tetraiodoaurate(III), has a tilted and distorted perovskite-type structure which is isotypic with its bromide analogue Rb2[AuIBr2][AuIIIBr4]. The structure contains compressed and elongated [AuI6] octahedra tilted away from each other and stacked alternately along th…
Abstract For the first time we studied Raman, exciton and EPR spectra of PbI 2 layered crystals of 2H polytype doped with high concentration of Mn impurity. A novel type of Fermi resonance was found. The anomalous temperature shift of the exciton band n = 1 was registered. It was shown that this shift can be explained…
Abstract Near‐spherical dendrimers can be used as templates for bottom‐up syntheses of semiconductor clusters. Starting from methanolic solutions of Cd 2+ , sulfide, and poly(amidoamine) dendrimers, CdS clusters precipitate at the dendrimers. A preparation inside the dendrimers is only possible when the protonation of…
Crystals of CsGd(PO3)4 have been grown by the flux technique from a mixture of CsH2PO4, Gd2O3 and H3PO4. CsGd(PO3)4 crystallizes in structure type IV of the MIMIII(PO3)4 (MI = alkali metal, MIII = rare earth or Bi) family of compounds. The structure consists of a three-dimensional framework made up of spiral (PO3)n ch…
Direct 1N-amination of the triazole-fused zinc phthalocyanine 2 and oxidation of the formed amino derivative 3 resulted in the generation of the very reactive intermediate, the dehydrometallophthalocyanine 4, which was not known previously. The latter was trapped in situ with different dienes, for example, furan, tetr…
The Sparkle/AM1 model is extended to ytterbium (III) complexes. Thus, a set of 15 complexes, with various representative ligands, chosen to be representative of all complexes of high crystallographic quality (R-factor <0.05 A) in the Cambridge Crystallographic Database, and which possess oxygen and/or nitrogen as coor…