Materials Literature
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We report an investigation of the heterogeneity in supercooled liquids and glasses using the non-Gaussianity parameter. We simulate selenium and a binary Lennard-Jones system by molecular dynamics. In the non-Gaussianity three time domains can be distinguished: an increase on the ps scale due to the vibrational (balli…
Monoclinic zirconia samples were irradiated with 300 MeV Ge and Ni ions at increasing ion fluences. Their structural evolution was monitored in situ by x-ray diffraction and ex situ by Raman spectroscopy. No amorphization of zirconia was observed in both cases. However, a transition from the monoclinic to the tetragon…
We present elastic and quasielastic neutron scattering measurements characterizing peculiar short-range charge-orbital and spin order in the layered perovskite material La1.5Sr0.5CoO4. We find that below T(c) approximately 750 K holes introduced by Sr doping lose mobility and enter a statically ordered charge glass ph…
The size distribution, band gap energy, and photoluminescence of silicon nanocrystals embedded in SiO2 have been measured by direct and independent methods. The size distribution is measured by coupling high-resolution and conventional electron microscopy in special imaging conditions. The band gap is calculated from…
Epitaxial BaTiO3(111)/SrTiO3(111) multilayered thin films have been investigated with various periods of stacking layer between 0.45/0.45 and 10/10 nm on Nb-doped SrTiO3(111) substrates by a pulsed-laser deposition technique. Upon decreasing the period of each layer, the spacing of (111) plane (d111) of the multilayer…
We present a molecular dynamics study of the single-particle dynamics of supercooled water confined in a silica pore. Two dynamical regimes are found. Close to the hydrophilic substrate molecules are below the mode coupling crossover temperature, T(C), already at ambient temperature. The water closer to the center of…
Contents: 5.1 Introduction 5.2 Concepts and definitions 5.3 The tight-binding picture of bonding 5.4 Adsorption of isolated adatoms 5.5 Alkali-metal adsorption: the traditional picture of on-surface adsorption 5.6 Substitutional adsorption and formation of surface alloys 5.7 Adsorption of CO on transition-metal surfac…
We have measured and calculated the magnetocaloric effect in macroscopic samples of oriented high-spin molecular clusters like Mn12 and Fe8 as a function of the temperature and both the intensity and the sweeping rate of the applied magnetic field. We have observed a high magnetic entropy variation around the blocking…
It is shown that a pulsed current driven through Ni nanowires provokes an irreversible magnetization reversal at a field distant from the spontaneous switching field $H_{sw}$ by $ΔH$ of as much as 40 % of $H_{sw}$. The state of the magnetization is assessed by magnetoresistive measurements carried out on single, isola…
The study deals with the Payne effect (a substantial decrease in the storage modulus of a particle-reinforced elastomer with an increase in the amplitude of mechanical oscillations). The influence of temperature, concentration of filler and amplitude and frequency of strains is analyzed on the mechanical response of f…
The thermoelectric power (TEP) of single-walled carbon nanotubes (SWNTs) is extremely sensitive to gas exposure history. Samples exposed to air or oxygen have an always positive TEP, suggestive of holelike carriers. However, at fixed temperature the TEP crosses zero and becomes progressively more negative as the SWNTs…
20 mm long ropes consisting of soundly aligned single-walled carbon nanotube (SWNT) ropes, synthesized by the catalytic decomposition of hydrocarbons, were employed for direct tensile strength measurements. The average tensile strength of SWNT rope composites is as high as 3.6±0.4 GPa, similar to that of carbon fibers…
We study the vicinal surface with adsorption below the roughening temperature, using the restricted solid-on-solid model coupled with the Ising model. By the product-wavefunction renormalization group method, we calculate the surface gradient $p$ and the adsorption coverage $Θ$ as a function of the Andreev field $η$ w…
Electrical transport properties of RNiO3 (R= Pr, Nd, Sm) thin films grown by pulse laser deposition have been studied. RNiO3 films grow in (100) direction on LaAlO3 (100) substrate. Unlike in polycrystalline solid, PrNiO3 film showed metallic behavior. The first order metal to insulator transition observed in polycrys…
Mesoporous materials such as Ti−HMS, prepared at ambient temperature, were studied both under continuous flow and closed reaction systems for the photocatalytic decomposition of NO. The results indicate Ti−HMS to be a good photocatalyst with a continuous reactivity under prolonged irradiation. The direct decomposition…
The orbital interaction between the sheets of graphite slabs, in which small numbers of sheets ( n ) are stacked in the ABAB fashion, is theoretically analyzed. We predict from the nodal properties in the interlayer orbital interaction that the spacing between the graphite sheets should be large (small) when n is even…
The three-dimensional structure of the hybrid cluster protein from Desulfovibrio vulgaris (Hildenborough) has been determined at 1.6 A resolution using synchrotron X-ray radiation. The protein can be divided into three domains: an N-terminal mainly alpha-helical domain and two similar domains comprising a central beta…
We describe the preparation of hairy nanospheres by grafting of polystyrene macromonomer chains onto polyorganosiloxane microgels. Our strategy was to obtain special surface-modified colloidal particles, which can be blended with linear polymer chains without depletion demixing found for standard colloid−polymer mixtu…
The surface modification of colloidal gold particles with the amino acid valine is demonstrated. Self-assembly of valine on the gold particles is accomplished in the aqueous phase, linkage with the gold particles possibly occurring through covalent interaction of the amine group with the surface gold atoms. Derivatiza…
Ordered arrays of palladium nanostructures have been obtained inside MCM-48 and SBA-15, using chemical vapor infiltration. Removal of the silica matrix affords porous three-dimensional Pd nanoballs and one-dimensional Pd nanowires, depending on the architecture of the silicate host.