Materials Literature
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We have studied details of the molecular origin of slow secondary relaxation near T(g) in a series of neat polyalcohols by means of dielectric spectroscopy and (2)H NMR. From glycerol to threitol, xylitol, and sorbitol the appearance of the secondary relaxation changes gradually from a wing-type scenario to a pronounc…
Polycrystalline ${\mathrm{Ni}}_{2.18}{\mathrm{Mn}}_{0.82}\mathrm{Ga}$ Heusler alloys with a coupled magnetostructural transition are studied by differential scanning calorimetry, magnetic and resistivity measurements. Coupling of the magnetic and structural subsystems results in unusual magnetic features of the alloy.…
By means of Monte Carlo simulations on a kinetic model, we demonstrate that the efficiency of a photoinduced phase change can in general be enhanced drastically by using a superstructure of an appropriate combination of two components. This is due to the accelerated nucleation of converted domains in the structural bl…
We study the low-velocity (0.1--100 $μ$m.s$^{-1}$) frictional properties of interfaces between a rough glassy polymers and smooth silanized glass, a configuration which gives direct access to the rheology of the adhesive joints in which shear localizes. We show that these joints exhibit the full phenomenology expected…
The structure of ${\mathrm{LiMoS}}_{2}$ has been experimentally determined. The approach of atomic pair distribution function analysis was used because of the lack of well-defined Bragg peaks due to the short structural coherence (\ensuremath{\sim}50 \AA{}) in this intercalation compound. The reduction of Mo by Li res…
The substitution of Mo(III) for Cr(III) in metal-cyanide clusters is demonstrated as an effective means of increasing the strength of the magnetic exchange coupling and introducing magnetic anisotropy. Synthesis of the octahedral complex [(Me(3)tacn)Mo(CN)(3)] (Me(3)tacn = N,N',N"-trimethyl-1,4,7-triazacyclononane) is…
A series of hydrophilic organic dendron ligands was designed and synthesized for stabilizing high-quality semiconductor and noble metal nanocrystals. The focal point of the dendron ligands is chosen to be a thiol group which is a universal coordinating site for compound semiconductor and noble metal nanocrystals. The…
We describe a synthetic procedure for preparation of large quantities of monodisperse thiol-stabilized gold colloids in toluene solution. The method is based on the solvated metal atom dispersion technique (SMAD), which is very suitable for preparation of large amounts of metal colloidal solutions, as well as of metal…
The use of surface-enhanced Raman spectroscopy (SERS) has recently seen a revitalization of interest with advances in surface coating technologies and other related areas. Recent reports have indicated that enhancement factors of up to 14 orders of magnitude can be achieved, providing the sensitivity requisite to trac…
The preparation of hollow nanoparticles with amino groups on the inner side via the stepwise complexation and selective decomplexation of poly(ethylene imine) is presented.
Layered double hydroxides (LDHs), containing intercalated oxometalate (Mo, W) species, were obtained by chimie douce reactions from NaNi1 − yCoyO2 cobalt substituted sodium nickelates (0.10 ≤ y ≤ 0.40). The X-ray diffraction (XRD), infrared (IR) and extended X-ray absorption fine structure (EXAFS) studies show that, i…
Expansion analysis shows that in second order, the weak boundary coupling of nematic liquid crystals should be depicted by two anchoring coefficients and an orthonormal vector triplet. Using this binomial anchoring energy, we have derived the analytical expression of the threshold and saturation properties of the twis…
First metal complexes containing the perfluoroacetylacetonato ligand have been prepared by the reaction of anhydrous Ln(OAc)3 (Ln = Eu, Tb, Tm) with heptafluoroacetylacetone, optionally in the presence of other ligands Ph3PO, bpy, and PyO.
The dynamics of image-potential states on Cu(119) have been studied with two-photon photoemission. Direction-dependent quasielastic scattering processes with large momentum transfer are attributed to the finite terrace-width distribution on the stepped surface. This effectively couples image-potential states via inter…
A cyclic porphyrin tetramer, consisting of two bis-phosphine substituted zinc(II) porphyrin units and two Rh(III)TPP units, is selected and amplified virtually quantitatively from a dynamic combinatorial library using 4,4'-bipy as a scaffold and using orthogonal binding modes.
[reaction: see text] A dendrimer wherein the branching points are mechanical in nature has been synthesized. It contains two identical covalently linked bis-dendrons and a core unit fused to two rings that encircle the two bis-dendrons. A "threading-followed-by-stoppering" approach is used in the template-directed syn…
Total neutron diffraction has yielded accurate bond lengths, Ag-C = Ag-N = 2.06 A and C-N = 1.16 A, for the disordered crystalline solid AgCN. This information cannot be obtained from analysis of Bragg scattering studies, because the (-Ag-CN-)(n) chains are randomly displaced along the chain axis relative to each othe…
Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature mom…
A triblock copolymer (PCL−PPG−PCL, M n = 1.38 × 10 4 ) of poly(ε-caprolactone) (PCL) and poly(propylene glycol) (PPG) was synthesized by ring-opening polymerization of ε-caprolactone. Cyclodextrin (CD)-type-dependent formation of inclusion complexes (ICs) between cyclodextrins and this triblock copolymer was studied.…
The relative stability between the ${P6}_{3}/m$ and ${P6}_{3}$ structures of \ensuremath{\beta}-silicon nitride $(\ensuremath{\beta}\ensuremath{-}{\mathrm{Si}}_{3}{\mathrm{N}}_{4})$ crystal has been examined using the ab initio pseudopotential method. We have performed the relaxation of atomic positions in the unit ce…