Materials Literature
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Three-dimensional (3D) ZnO hybrid structure was fabricated by growing a ZnO buffer layer, a ZnO nanowire array, and a ZnO film continuously through the control of supersaturation conditions. Lower and upper ends of vertically aligned nanowires in this hybrid structure formed seamless interfacial contacts with the buff…
Using a synchrotron radiation source and a diamond anvil cell, we measured the pressure dependence of the lattice parameters of a polycrystalline Ti4AlN3 sample up to a pressure of 55 GPa. No phase transformations were observed. As observed in Ti3SiC2,Ti3Si0.5Ge0.5C2, and Zr2InC, the compressibility of Ti4AlN3 along t…
A continuum model yielding dispersion relations for long-wavelength acoustic and optical phonons in two-dimensional graphite and achiral single-walled carbon nanotubes is developed. Close relations with the theory of thin elastic plates and cylindrical shells are established. The effective thickness of a nanotube dete…
Highly ordered cadmium sulphide (CdS) nanoparticle (NP) arrays were fabricated on silicon (Si) substrates using ultrathin alumina membranes as evaporation masks. The CdS NPs are polycrystalline and are composed of ultrasmall closely packed nanocrystallites. These crystallites increase in size as the duration of the Cd…
Raman active phonon frequencies and corresponding vibrational eigenmodes are reported for two M2AlC ceramics, Ti2AlC and Cr2AlC, by means of first-principles calculations. The theoretical modes are approved by the experimental Raman spectrum for Ti2AlC. Compared with that of the Ti3SiC2 counterpart, the number of Rama…
Abstract A new analytical form for bond and angle potentials suitable for obtaining mesoscale effective force fields from target distributions is reported. Applications to realistic coarse‐grained models of atactic polystyrene and polyamide‐6,6 are described. The potential optimization procedure, despite its simplicit…
In this work, a photothermal experiment is designed and conducted to characterize the thermal transport in carbon nanotubes (CNTs) along the axial direction exclusively. We characterize the thermal contact resistance between CNTs and the substrate. The measured value demonstrates a sound thermal contact between them.…
A promising generation of extremely low frequency magnetic field sensors, based on multilayer composites (MLCs) of magnetostrictive Terfenol-D (Tb1−xDyxFe2−y) and piezoelectric Pb(Mg1∕3Nb2∕3)O3–PbTiO3, has been developed. Our MLC magnetoelectric sensor presently shows a limit in (i) working frequency of ∼5×10−3Hz; and…
We demonstrate that carefully prepared (Ga,Mn)As films can show large magnetic moments per atom across a wide range of Mn concentrations, indicating almost full participation of the Mn in the ferromagnetism. Applying sum rules to Mn ${L}_{2,3}$ x-ray magnetic circular dichroism (XMCD) spectra yields a magnetic moment…
The electronic structure of the rhombohedral $\mathrm{La}\mathrm{Co}{\mathrm{O}}_{3}$ perovskite is calculated for a number of structures with varying $\mathrm{Co}{\mathrm{O}}_{6}$ octahedra geometry. The calculations are based on the generalized gradient approximation (GGA) to the density functional theory and, in or…
Ein Stück oder zwei! Durch selektives Ätzen verzwillingter Keime, das durch HCl und Luftsauerstoff vermittelt wird, sind perfekte einkristalline Silbernanowürfel in hohen Ausbeuten und unterschiedlichen Größen (30–130 nm) zugänglich. Das Chloridion verstärkt die Oxidation und verhindert die Aggregation, das Proton ver…
Phase resolved partial discharge measurements offer excellent possibilities to characterize the properties of defects in insulation materials. The appearance of the partial discharge pattern reflects the defect's geometry, the availability of the initial electron, and the properties of the contributing materials. With…
The exponential correlation function is theoretically incorrect in the entire frequency range of interest for processes described in terms of linear response theory. The Lorentzian lineshape results from an inconsistent assumption of exponential correlation at timescales smaller than the relaxation time. A new correla…
We report on the fabrication and current-voltage (IV) characteristics of very narrow, strip-like arrays of metal nanoparticles. The arrays were formed from gold nanocrystals self-assembled between in-plane electrodes. Local cross-linking of the ligands by exposure to a focused electron beam and subsequent removal of t…
This paper investigates the thermal stability of single and multi-walled carbon nanotubes (CNTs). The modeling and simulation of the problem are carried out using molecular dynamics simulation incorporating the Berendsen thermostat scheme for both open-ended and close-capped CNTs. It is found that single-walled CNTs a…
We use experiment and theory to demonstrate a mechanism for directive emissions, which involves a double-plate resonance cavity made with metamaterials. In contrast to other mechanisms employing Fabry-Pérot cavities, photonic crystals, or zero index materials, our system is significantly thinner than the working wavel…
We measured the bias stress characteristics of poly(thiophene) semi-crystalline thin-film transistors (TFTs) as a function stress times, gate voltages and duty-cycles. At room temperature, the bias stress has two components: a fast reversible component and a slow irreversible component. We hypothesize that the irrever…
The fluctuation-dissipation relation (FDR) is measured on the dielectric properties a polymer glass (polycarbonate). It is observed that the fluctuation dissipation theorem is strongly violated for a quench from above to below the glass transition temperature. The amplitude and the persistence time of this violation a…
The origins of an ultrahigh dielectric constant in polycrystalline CaCu3Ti4O12 (CCTO) were studied using the combination of impedance spectroscopy, electron microscopy, and scanning probe microscopy (SPM). Impedance spectra indicate that the transport properties in the 0.1Hz–1MHz frequency range are dominated by a sin…
We propose an equivalent circuit representation of the photogenerated charge separation and propagation in dye sensitized polycrystalline semiconductor in contact with a redox electrolyte. The suggested equivalent circuit for this type of photocell is based on an electrical transmission-line, and uses distributed phot…