Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
This discussion focuses on our recent approaches at aiming to optimize surface-enhanced Raman scattering (SERS) activity for transition metals (group VIII B elements), by intentionally fabricating desired surface nanostructures or synthesizing nanoparticles. The SERS activity of transition metals critically depends on…
We show from density-functional calculations that Pb(100) thin films exhibit quantum size effect with a bilayer periodicity in film energies, film relaxations, and work functions, which originate from different symmetry of the stacking geometry of odd and even layer films. The bilayer periodicity of the film energy is…
The relaxation of strongly confined electrons and holes from higher excited states to their lowest excited states in colloidal PbSe nanocrystals has been time resolved using femtosecond transient absorption spectroscopy. In contrast to II-VI and III-V semiconductor nanocrystals, both electrons and holes are strongly c…
We have measured Re 5d spin and orbital magnetic moments in the ferrimagnetic double perovskite Sr2CrReO6 by x-ray magnetic circular dichroism at the L2,3 edges. In fair agreement with recent band structure calculations [G. Vaitheeswaran, V. Kanchana, and A. Delin, Appl. Phys. Lett. 86, 032513 (2005)], at the Re site…
Hall effect is detected in organic field-effect transistors, using appropriately shaped rubrene (C42H28) single crystals. It turned out that inverse Hall coefficient, having a positive sign, is close to the amount of electric-field induced charge upon the hole accumulation. The presence of the normal Hall effect means…
We present ab-initio density functional (DFT) calculations of the vibrational spectra of neutral Magnesium phthalocyanine (MgPc) molecule and of its Raman scattering intensities.
We synthesized aligned multiwalled carbon nanotube multilayers by aerosol-assisted catalytic chemical vapor deposition through sequential injections of aerosols containing both carbon and catalyst precursors. Each sequence was traced by a specific duration or precursor mixture, with the carbon source being possibly en…
Individual multiwalled carbon nanotubes grown by chemical vapor deposition (CVD) were tensile tested within the chamber of an electron microscope using an atomic force microscope-based technique. Weibull–Poisson statistics could accurately model the nanotube tensile strength data. Weibull shape and scale parameters of…
Stable aqueous iron oxide nanoparticle dispersions were prepared by coprecipitation of ferrous (Fe2+) and ferric (Fe3+) aqueous solution by a base in the presence of graft copolymers, poly(glycerol monoacrylate)-g-poly(PEG methyl ether acrylate) (PGA-g-PEG). PGA-g-PEG was prepared by acidic hydrolysis of poly(solktal…
We report an energy gap for hole photoexcitation in ferromagnetic ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{P}$ that is tunable by Mn concentration ($x\ensuremath{\le}0.06$) and by compensation with Te donors. For $x\ensuremath{\sim}0.06$, electrical transport is dominated by excitation across this gap…
We propose a model for the formation of drying cracks in a viscoplastic material. In this model, we observe that when an external force is applied to a viscoplastic material before drying, the material memorizes the effect of the force as a plastic deformation. The formation of the drying cracks is influenced by this…
The Langer-Schwartz equations for precipitation are formulated to calculate nucleation, growth and coarsening of second phase precipitates under non-isothermal situations. A field-theoretic steady-state nucleation rate model is used in the analysis. The field-theoretic nucleation rate is compared with the classical nu…
The 'two-electron' doped rare earth mangnites Ca_1-x Ce_x MnO_3 (x = 0.1,0.2) are probed using resistivity, ac susceptibility and electron paramagnetic resonance (EPR) measurements across their respective charge ordering (CO) temperatures T_CO = 173 K and 250 K. The EPR 'g' factor and intensity as well as the transpor…
A new low-molecular-mass gelator with one TTF and one urea group is described. It was found that the gel formation can be tuned by formation of CT complexes and oxidation.
We report here "strain glass," a new glassy phenomenon in ferroelastic-martensitic system of Ni-rich intermetallic Ti(50-x)Ni(50+x) (x > 1), where local strain is frozen in disordered configuration below a critical temperature Tg. The ac elastic modulus shows a minimum at Tg, which exhibits logarithmic frequency depen…
We report here a simple one-step protocol for the preparation of near-monodisperse gold hydrosols in the small size regime (<5 nm). The particle size can be controlled by varying the concentration of the stabilizing polymer, which can be readily displaced by thiol ligands to yield monolayer protected clusters of the u…
The underlying mechanisms of stability, metastability, or instability of the Cassie-Baxter and Wenzel wetting modes and their transitions on superhydrophobic surfaces decorated with periodic micropillars are quantitatively studied in this article. Hydraulic pressure, which may be generated by the water-air interfacial…
Diffusion, coalescence, and reconstruction of vacancy defects in graphene layers are investigated by tight-binding molecular dynamics (TBMD) simulations and by first principles total energy calculations. It is observed in the TBMD simulations that two single vacancies coalesce into a 5-8-5 double vacancy at the temper…
The biocompatibility of a scaffold for tissue engineered constructs is essential for the outcome. Bacterial cellulose (BC) consists of completely pure cellulose nanofibrils synthesized by Acetobacter xylinum. BC has high mechanical strength and can be shaped into three-dimensional structures. Cellulose-based materials…
The crystal structure and magnetic properties of polycrystalline Sr 2 (Fe 1− x Ni x )MoO 6 (0.0 ⩽ x ⩽ 0.2) synthesized via a mechanical activation route have been investigated. Rietveld refinement of the x-ray diffraction data indicates that the long-range order parameter ( S ) among octahedral B sites in Sr 2 (Fe 1−…