Materials Literature
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Organization of photoresponsive azobenzene ligands within a 3D porous framework imparts new molecular-level functionality. The trans⇌cis conformation change of azobenzene ligands triggered by photoirradiation transduces photo energy into mechanical work, which can be used for opening and closing valves (see picture).
The influence of the Rashba spin-orbit coupling on the electron spin dynamics is investigated for a ballistic semiconductor quantum wire with a finite width. We monitor the spin evolution using the time-dependent Schrödinger equation. The pure spin precession characteristic of the 1D limit is lost in a 2D wire with a…
Iterative multiscale methods for electronic structure calculations offer several advantages for large-scale problems. Here we examine a nonlinear full approximation scheme (FAS) multigrid method for solving fixed potential and self-consistent eigenvalue problems. In principle, the expensive orthogonalization and Ritz…
Vapor pressures were measured for the system chloroform/polyethylene oxide (peo, weight average molar mass = 1000 kg/mol) at 25 degrees centigrade as a function of the weight fraction w of the polymer by means of a combination of head space sampling and gas chromatography. The establishment of thermodynamic equilibria…
Recent results using a new combined small-angle/wide-angle X-ray scattering (SAXS/WAXS) beam line at the European Synchrotron Radiation Source (ESRF) will be presented. This beam line is specifically designed to be able to handle complicated sample environments required to perform time-resolved experiments mimicking p…
A hollow-structured and highly ordered mesoporous aluminosilicate with a 3D pore network and significantly improved hydrothermal stability has been successfully prepared by a simple method. To elucidate its novel structure and improved hydrothermal stability, a model for the formation of such a hollow spherical materi…
The application of theoretical methods based on the density functional theory with hybrid functionals provides good estimates of the exchange coupling constants for polynuclear transition metal complexes. The accuracy is similar to that previously obtained for dinuclear compounds. We present test calculations on simpl…
Nature exploits self-organization of soft materials in many ways, to produce cell membranes, biopolymer fibers and viruses, to name just three. Mankind is now able to design materials at the nanoscale, whether through atom-by-atom or molecule-by-molecule methods (top-down) or through self-organization (bottom-up). The…
A uniform stripe-shaped domain (SSD) structure was obtained in the initial ferroelectric liquid crystal (FLC) alignment by rubbing the polyimide films doped with silicon naphthalocyanine. Such a surface-stabilized FLC cell exhibits a high contrast ratio and excellent bistability. Atomic force microscope images and pre…
Amorphous carbon (a-C) films were fabricated in pure methane plasma by using the radio frequency plasma-enhanced chemical vapor deposition (RF PECVD) system. Surface morphology and roughness of the films were examined as a function of substrate temperature by atomic force microscopy (AFM). Field emission from the a-C…
We analyse experimental ac conductivity data of various glassy (61SiO 2 ·35Li 2 O·3Al 2 O 3 ·P 2 O 5 and alkali triborates of formulae M 2 O·3B 2 O 3 with M = Li, Na, K or Rb) and crystalline ionic conductors (Li 0.18 La 0.61 TiO 3 and yttria stabilized zirconia with a 16% molar yttria content, (Y 2 O 3 ) 0.16 (ZrO 2…
In this paper we make some general comments on the methods used for modelling glasses and use glassy GeSe 2 as an example. We then emphasize recent work on As–Se glasses, including glassy As 2 Se 3 and amorphous AsSe. The topology and electronic and vibrational properties of the models are discussed and with their use…
We use classical molecular dynamics simulations to study the motion of sodium atoms in amorphous Na 2 O – 4SiO 2 over a wide range of temperatures below and above the glass transition temperature T g . We find that the region of space most visited by the sodium atoms forms a network of connected pockets that we call c…
We report on the photo-response behavior of n-ZnO/p-Si photodiodes. Semiconducting n-ZnO films have been deposited on p-Si substrate by RF sputtering at 300, 480 and 550°C. An optimum static photo-response was achieved from the photodiode prepared at 480°C as characterized by photocurrent measurements using a continuo…
A decrease in tilt angle generation for a nematic liquid crystal (NLC) with negative dielectric anisotropy on a blended homeotropic polyimide (PI) surface containing trifluoromethyl moieties was investigated. The decrease in tilt angle (below 90°) of NLC on the blended PI surface containing a homogeneous PI structure…
A different class of layered systems derived from ${\mathrm{ThCr}}_{2}{\mathrm{Si}}_{2}$-type materials is introduced and studied. We present preparation, x-ray analysis, band-structure, and total-energy calculations of ${\mathrm{KCu}}_{2}{\mathrm{Se}}_{2},$ a semimetallic representative of this class. The crystal has…
Inductively coupled plasma chemical vapor deposition combined with substrate biasing using pure methane was applied to low-temperature synthesis of carbon nanotubes. We found that the resultant carbon nanotubes were crystalline even at a growth temperature of 500°C. The growth mechanism of the crystallized carbon nano…
The conductivity dispersion in several alkali phosphate glasses is examined as the glass structure changes from an interconnected 'mesh' network to one of phosphate chains cross-linked by alkali ions. For metaphosphate glasses the dispersion varies in response to the size of the mobile ion relative to the mean spacing…
This study examined the solid-state structure and oxygen transport properties of smectic poly(diethylene glycol 4,4‘-bibenzoate) (PDEGBB). The polymer was quenched from the isotropic melt to the smectic liquid crystalline glass and subsequently isothermally crystallized by heating above the glass transition temperatur…
A single crystal of perovskite bilayer manganite La 1.2 Sr 1.8 Mn 2 O 7 has been studied by the 55 Mn NMR technique. The observed spectra at 4.2 K in zero external magnetic field are broad and spread in the frequency range 310–480 MHz. The shape of the spectrum depends strongly on the rf radiation field for exciting a…