Materials Literature
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A theoretical study of depletion interactions between pairs of small, globular colloids dispersed in a lyotropic nematic of hard, rodlike particles is presented. We find that both the strength and range of the interaction crucially depends on the configuration of the spheres relative to the nematic director, and on th…
Bi-based layered ferroelectric thin films of Sr2Bi4Ti5O18 (SBTi) were prepared by pulsed-laser deposition. The c-axis-oriented SBTi films were grown on SrRuO3 seeded Pt/TiO2/SiO2/Si substrates while polycrystalline SBTi films were grown on Pt/TiO2/SiO2/Si substrates. The measurements of ferroelectricity revealed that…
Single-phase paraelectric ZrTiO4 thin films were synthesized at various temperatures using direct-current magnetron reactive sputtering. The dielectric constants (ε) and dielectric losses (tan δ) of as-deposited and annealed films were measured in the 100 kHz range using a Pt upper electrode and a phosphorous-doped Si…
We have deposited CaTiO3 thin films on SrRuO3 electrode layers on SrTiO3 and LaAlO3 substrates by pulsed laser deposition. The low-frequency dielectric properties were measured from 4 to 300 K. We found that the dielectric constants of 1-μm-thick CaTiO3 films are very close to that observed in the bulk materials. The…
The unit cell structures of two ferrielectric liquid-crystal phases are determined from ellipsometric studies of freestanding films in a nondistorting rotatable electric field. A highly biaxial mode with out-of-plane distortions describes all of the data from two different compounds. Qualitative and quantitative featu…
Single-walled carbon nanotube (SWNT) probe microscopy tips were grown by a surface growth chemical vapor deposition method. Tips consisting of individual SWNTs (1.5–4 nm in diameter) and SWNT bundles (4–12 nm in diameter) have been prepared by design through variations in the catalyst and growth conditions. In additio…
We study the plasmon resonances of 10 (nm)--100 (nm) two-dimensional metal particles with a non-regular shape. Movies illustrate the spectral response of such particles in the optical range. Contrary to particles with a simple shape (cylinder, ellipse) non-regular particles exhibit many distinct resonances over a larg…
The literature data on the entropy and heat capacity of 33 glass-forming liquids have been used to examine the validity of the Adam–Gibbs relation between a liquid’s configurational entropy, Sconf, and its molecular kinetics. The critical entropy, sc*, of kB ln 2 (=0.956×10−23 J molecule−1 K−1) in the equation is less…
We report on long-range electronic effects caused by hydrogen-carbon interaction at the graphite surface. Two types of defects could be distinguished with a combined mode of scanning tunneling microscopy and atomic force microscopy: chemisorption of hydrogen on the basal plane of graphite and atomic vacancy formation.…
We performed inelastic neutron scattering on the 2D Shastry-Sutherland system SrCu2(11BO3)2 with an exact dimer ground state. Three energy levels at around 3, 5 and 9 meV were observed at 1.7 K. The lowest excitation at 3.0 meV is almost dispersionless with a bandwidth of 0.2 meV at most, showing a significant constra…
Recently Leuenbeger and Loss suggested a theory of phonon-assisted relaxation in a molecular nanomagnet Mn-12 that "contrary to previous results is in reasonably good agreement ... with all experimental parameter values known so far". The purpose of this Comment is to show that the model of Leuenberger and Loss and it…
The atomic ordering in complex perovskite alloys is investigated by the cluster variation method (CVM). For the 1/3\{111\}-type ordered structure, the order-disorder phase transition is the first order, and the order parameter of the 1:2 complex perovskite reaches its maximum near x=0.25. For the 1/2\{111\}-type order…
Recently, Bellessa et al in a Physical Review Letter entitled "Phonon-Assisted Tunneling in High-Spin Molecules: Experimental Evidence", reported observation of a peak in the imaginary part of the ac-susceptibility of Mn-12 molecular nanomagnet, that decreases strongly below 0.1 K down to 0.02 K. They explained this e…
We investigate the electron-phonon (e-ph) interaction in single-wall carbon nanotube samples at room temperature using femtosecond time-resolved photoemission. By probing electrons from the vicinity of the Fermi level we are able to study the e-ph interaction in the metallic nanotube species only. The observed electro…
The aim of this study is the determination of the residual stress state and the analysis of the microstructure of ZrO 2 oxide layers (mainly the tetragonal to monoclinic phase ratio) formed on different zirconium alloy plates oxidized in steam at 400°C for several lengths of time, using x-ray diffraction techniques. T…
To measure internal strains in an Al MMC, time-of-flight (TOF) ncutron diffraction was used on the ENGIN instrument at ISIS, RAL, in Oxfordshire, and a monochromated X-ray beam was employed on the BM16 beamline at the ESRF in Grenoble. The development of intergranular stresses between groups of grains possessing certa…
High-cell-density fed-batch cultures of Pseudomonas putida were carried out for the production of medium-chain-length polyhydroxyalkanoates (PHAs) using oleic acid as a carbon source. By employing an optimal feeding strategy without the limitation of any nutrient, a high cell concentration of 173 g/L was achieved, but…
We have measured normal quasi-equilibrium forces between adsorbed layers formed on hydrophilic surfaces in aqueous solutions of telechelic poly(ethylene oxide) end-terminated with octadecyl groups. At low polymer concentrations, c pol, a monolayer adsorbs, which has properties similar to the monolayer of adsorbed nonh…
Mono- (3a,b) and binuclear (4a,b) tetradentate NiII complexes of a series of 26-membered macrocyclic salen dimers, [salen(CH2)]2, are prepared in good yield by solvent-controlled reaction with Ni(OAc)2. The mononuclear complex 3b crystallizes in the trigonal space group 3P1(#144), a = 18.2566(2) A, c = 15.9244(2) A, V…
New cyclic metalloporphyrin hosts, 6 and 7, have been prepared. At 0.33 mM in dichloromethane at 25 °C, they accelerate 65-fold and 840-fold respectively the reaction of diene 1 and dienophile 2 and also bind the hetero Diels−Alder product 3 very strongly. More importantly, small single crystals of solvated 6, 7, and…