Materials Literature
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Molecular dynamics (MD) simulations of diffusion couple tests were conducted between carbon (diamond/graphite) and iron at three different temperatures (300, 800 and 1600 K) and contact times (0, 40 and 80 ps) to investigate the chemical interaction between carbon and iron. Two different carbon structures, namely, dia…
Using first-principles density functional calculations with AlH 3 , KMgH 3 , LiMgH 3 , NaBeH 3 , NaMgH 3 , and RbMgH 3 as model systems we have analyzed the band structure of hydrides. It is shown that hydrides can possess the features of semiconductors with n - and/or p -type electrical conductivity. We have found th…
A unique series of halogenidoiron(III) complexes of the open-chain tetrapyrrolic ligand 2,2'-bidipyrrin (bpd) ([FeX(bdp)] X=F, Cl, Br, I) was prepared from simple pyrrolic and bipyrrolic precursors and iron chloride by a one-pot condensation/metalation strategy, followed by salt metathesis with CsF, LiBr, or NaI. Crys…
The nature of $\mathrm{O}\text{\ensuremath{-}}\mathrm{H}$ wag vibrations in the cubic proton conducting perovskite-type oxides, ${\mathrm{BaIn}}_{x}{\mathrm{Zr}}_{1\ensuremath{-}x}{\mathrm{O}}_{3\ensuremath{-}x∕2}$ $(x=0.20--0.75)$ have been investigated by means of inelastic neutron scattering. Our spectroscopic resu…
Within continuum dislocation theory the plastic deformation of bicrystals under plane strain constrained shear is considered. An analytical solution is found in the symmetric case (for twins) which exhibits the energetic and dissipative thresholds for dislocation nucleation, the Bauschinger translational work hardenin…
One of the primary factors affecting the failure in high strength silicon carbide (SiC)–silicon nitride (Si 3 N 4 ) nanocomposites is the placement of spherical nano-sized SiC particles in micro-sized Si 3 N 4 grains. In order to analyze this issue, the cohesive finite element method (CFEM) based dynamic fracture anal…
Ultrasonic velocity measurements are used to examine the elastic properties of the magnetoelectric compound $\mathrm{Cu}\mathrm{Fe}{\mathrm{O}}_{2}$ in the vicinity of the magnetic and structural phase transitions near $14\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Strong softening of modes related to ${C}_{66}$ occurs at…
X-ray resonant scattering has been used to measure the magnetic order of the Dy ions below $40\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in multiferroic $\mathrm{Dy}{\mathrm{Mn}}_{2}{\mathrm{O}}_{5}$. The magnetic order has a complex behavior. There are several different ordering wave vectors, both incommensurate and comm…
OBJECTIVE: A novel nanocomposite has recently been developed based on polyhedral oligomeric silsesquioxane attached by direct reaction onto a urethane segment, as a potential vascular graft material; its trade name is UCL-Nano. The UCL-Nano has been demonstrated to have similar viscoelastic properties to the walls of…
Scanning tunneling microscopy and spectroscopy have been used to investigate the electronic structure of non-stoichiometric ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ islands with a vanadyl termination grown on Au(111). The spectroscopic measurements reveal the correlation gap of bulk ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ that v…
We report the growth of ultralong β-Ga(2)O(3) nanowires and nanobelts on silicon substrates using a vapor phase transport method. The growth was carried out in a tube furnace, with gallium metal serving as the gallium source. The nanowires and nanobelts can grow to lengths of hundreds of nanometers and even millimeter…
Two-dimensional nanostructures have a variety of applications due to their large surface areas. In this study, the authors present a simple and convenient method to realize two-dimensional NiO nanowalls by thermal treatment of a Ni thin film deposited by sputtering onto a stainless steel substrate. The substrate surfa…
Density functional theory is used to study atomic oxygen absorption into subsurfaces of various platinum-based alloys to investigate the effects of alloyed metals on the thermodynamics and kinetics of this process. The results show that alloying Pt with Ir and Rh increases the absorption energy barrier compared with p…
We describe, in this paper, the sol-gel synthesis of di-ureasil based nanocomposites prepared in situ in the presence of organically capped CdSe quantum dots (QDs) or CdSe QDs which have been coated with a ZnS shell. For the latter a new chemical route to coat the CdSe QDs with ZnS shells was investigated and is now r…
Mononuclear Zn, Cd, and Hg 1,2-benzenedithiolates with intramolecular NH...S hydrogen bonds, [M(II){1,2-S2-3,6-(RCONH)2C6H2}2](2-) (R = CH 3, t-Bu; M = Zn, Cd, Hg), were synthesized and characterized by X-ray analysis and spectral measurements. The presence of intramolecular NH...S hydrogen bonds was established by th…
A theoretical model is proposed that describes the generation of deformation twins near brittle cracks of mixed I and II modes in nanocrystalline metals and ceramics. In the framework of the model, a deformation twin nucleates through stress-driven emission of twinning dislocations from a grain boundary distant from t…
A general nonaqueous route for the synthesis of phase-pure transition-metal niobate (InNbO(4), MnNb(2)O(6), and YNbO(4)) nanocrystals was developed based on the one-pot solvothermal reaction of niobium chloride and the corresponding transition-metal acetylacetonates in benzyl alcohol at 200 degrees C. All samples were…
The self-assembly of Pluronic block copolymers in dispersions of single-wall carbon nanotubes (SWNT) was investigated by spin probe electron paramagnetic resonance (EPR) spectroscopy. Nitroxide spin labeled block copolymers derived from Pluronic L62 and P123 were introduced in minute amounts into the dispersions. X-ba…
The structure of a monolayer phase of $\mathrm{Ti}{\mathrm{O}}_{x}$ on Pt(111) showing a zigzag-like contrast is investigated by scanning tunneling microscopy (STM) and density-functional calculations. Because of its peculiar defectivity, strongly dependent on the postdeposition thermal treatments, this system is an i…
Abstract In this study, high‐performance thermoset polymer composites are synthesized by using both long fibers and nanoclays. Epoxy and phenolic resins, the two most important thermoset polymers, are used as the polymer matrix. The hydrophobic epoxy resin is mixed with surface modified nanoclay, while the hydrophilic…