Materials Literature
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We calculate structural and electronic properties of ${\mathrm{CaCu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$ from ambient pressure up to 10.0 GPa using total-energy first-principles methods. Analysis of the simulated high-pressure structure suggests a pressure-induced structural phase transition between 3 and 4 GPa wi…
Thermoelectric air-conditioners (TEACs) are becoming much concerned due to their many advantages, but the low COPs limit their broad applications. The two key factors to raise the COPs of TEACs are both the improvement of thermoelectric materials and the optimum design of hot side heat sinks. This paper provides a the…
Metal-insulator transitions strongly coupled with lattice were found in ${\mathrm{Bi}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{NiO}}_{3}$. Synchrotron x-ray powder diffraction revealed that pressure ($P\ensuremath{\sim}3\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, $T=300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$), temper…
Self-absorption and radiation trapping in Er3 + -doped TeO2-based glasses, M. Mattarelli, M. Montagna, L. Zampedri, A. Chiasera, M. Ferrari, G. C. Righini, L. M. Fortes, M. C. Gonçalves, L. F. Santos, R. M. Almeida
BACKGROUND: The availability of suitable recombinant protein is still a major bottleneck in protein structure analysis. The Protein Structure Factory, part of the international structural genomics initiative, targets human proteins for structure determination. It has implemented high throughput procedures for all step…
We performed high pressure resonant Raman experiments on well characterized purified single-wall carbon nanotubes up to $40\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ using argon as pressure transmitting medium. We used two different excitating wavelengths, at $632.8\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and $514.5\phan…
Chitosan, the N-deacetylated derivative of chitin, is a potential biopolysaccharide owing to its specific structure and properties. In this paper, we report on the synthesis of 24 new chitosan derivatives, N-alkyl chitosans (NAC) and N-benzyl chitosans (NBC), that are soluble in dilute aqueous acetic acid. The differe…
Effect of hydrostatic pressure and magnetic field on electrical resistance of the Kondo-like perovskite manganese oxide, La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$ with a ferrimagnetic ground state, have been investigated up to 2.1 GPa and 9 T. In this compound, the Mn-moments undergo double exchange mediated ferromagnetic…
We explore how chemical patterning on surfaces can be used to control drop wetting. Both numerical and experimental results are presented to show how the dynamic pathway and equilibrium shape of the drops are altered by a hydrophobic grid. The grid proves a successful way of confining drops and we show that it can be…
CdP2 nanoclusters were fabricated by incorporation into pores of zeolite Na-X and by laser ablation. Absorption and photoluminescence (PL) spectra of CdP2 nanoclusters in zeolite were measured at the temperatures of 4.2, 77 and 293 K. Both absorption and PL spectra consist of two bands blue shifted with respect to bul…
Martensitic phase transitions appear in a diverse range of natural and engineering material systems. Examination of the energetics and kinetics of the transformation requires an understanding of the atomic mechanism for the transformation. A systematic pathway generation and sorting algorithm is presented and applied…
We have modeled the layer-by-layer assembly process of flexible polyelectrolytes on flat surfaces. The multilayer has a three-zone structure. An exponential growth is found for the first several layers, followed by a linear growth for subsequent layers evolving towards a steady state. While adjacent layers are highly…
We discuss the transport anomalies associated with the development of heavy electrons out of a neutral spin fluid using the large-N treatment of the Kondo-Heisenberg lattice model. At the phase transition in this model the spin excitations suddenly acquire charge. The Higgs process by which this takes place causes the…
It is shown that perfect imaging of a point source both in near- and far-field regions contradicts electrodynamics although ``superlensing'' is impossible only in the far-field region. These general statements are illustrated by detailed study of evanescent wave propagation in a photonic crystal that is known to be a…
Cobalt-doped ZnO (Co2+:ZnO) films were studied by magnetic circular dichroism (MCD) spectroscopy. A broad 300 K ferromagnetic MCD signal was observed between 1.4 and 4.0 eV after introducing shallow donor states by exposure of paramagnetic Co2+:ZnO films to zinc vapor. The new sub-bandgap ferromagnetic MCD intensity i…
We study the influence of structural lattice fluctuations on the elastic electron transport in single-wall carbon nanotubes within a density-functional-based scheme. In the linear-response regime, the linear conductance is calculated via configurational averages over the distorted lattice. Results obtained from a froz…
We study triangular lattice spin-$1∕2$ system with antiferromagnetic Heisenberg and ring exchanges using variational approach focusing on possible realization of spin-liquid states. Trial spin liquid wave functions are obtained by Gutzwiller projection of fermionic mean-field states and their energetics is compared ag…
Structural and magnetic transformations in the Heusler-based system ${\mathrm{Ni}}_{0.50}{\mathrm{Mn}}_{0.50\ensuremath{-}x}{\mathrm{Sn}}_{x}$ are studied by x-ray diffraction, optical microscopy, differential scanning calorimetry, and magnetization. The structural transformations are of austenitic-martensitic charact…
Abstract The wavelength dependence of the third‐order optical nonlinearity and response of the J‐like aggregates of a cyanine dye called NK‐3261 in a neat film were measured by the femtosecond degenerate four‐wave mixing (DFWM) technique under resonant conditions. The temporal profile of the DFWM signal of NK‐3261 J‐l…
Abstract New asymmetric (salen)Mn III and UO 2 complexes containing a calix[4]arene unit in the ligand framework were synthesized. The UO 2 complexes were characterized by 1 H‐, 13 C‐, 2D TOCSY and T‐ROESY NMR spectroscopy. Furthermore, the structure of one UO 2 complex was determined by single‐crystal X‐ray analysis.…