Materials Literature
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The characteristics of the diffuse phase transition of Pb(Fe2/3W1/3)O3 relaxor ceramics doped with different amounts of Mn are investigated. The freezing temperature Tf, obtained by fitting the ω,Tmax to the Vogel–Fulcher relationship, clearly changes with the Mn content. It increases as the Mn content increases, appr…
The formation of nanosized crystallites of magnetite, Fe3O4, by heat treatment of a glass containing iron oxide was investigated. The magnetic properties of the glass ceramic manufactured strongly depend on the heat treatment conditions. The evolution of size distribution and volume fraction of the nanocrystallites fo…
Fresnoite, Ba2TiOSi2O7, has been predicted structurally to be a new ferroelectric. Detection of both ac and dc dielectric hysteresis verifies the prediction. The spontaneous polarization Ps estimated from the hysteresis at 1.2 MV m−1 ac is ∼0.2 C m−2 at 295 K, comparable with the minimum Ps observed in one-dimensional…
Alignment control of mesogenic groups in a photocrosslinkable polymer liquid crystalline film was achieved by linearly polarized (LP) ultraviolet (UV) irradiation followed by heating. The alignment direction was parallel to the electric vector of the incident LPUV light and the tilt angle of the mesogenic groups could…
Variable temperature scanning-tunneling-microscopy/spectroscopy studies on single crystals and epitaxial thin films of hole-doped manganites, which show colossal magnetoresistance, have been done. We have investigated the variation of the density of states (DOS), at and near the Fermi energy ${(E}_{f}),$ as a function…
We report the variation of the structure and the electronic properties of amorphous nitrogenated carbon films (a-CH:Nx) prepared in dual electron cyclotron resonance-radio-frequency plasma from different mixtures of methane and nitrogen. Electron energy-loss spectroscopy, Auger electron spectroscopy, spectroscopic ell…
The transmission and reflection coefficients of a carbon nanotube with a scatterer are calculated in a tight-binding model. The result obtained in a k · p scheme is shown to be essentially valid, including the complete absence of back scattering for scatterers with range larger than the lattice constant, unless the st…
We study the transmission properties of light through the Fibonacci-class quasiperiodic multilayers. The trace map of the propagation matrices, its invariant of motion, and the expression for the transmission coefficient are obtained. For the normal incidence of light, the transmission coefficient exhibits a switchlik…
units, linerly coordinated silver ions, and vacant oxygen sites (see picture; Ag, Cu, and O are represented by white, large black, and small black spheres, respectively). The last feature allows for a rich solid-state redox chemistry.
Recent experiments indicate that the spin-density waves (SDWs) in $(\mathrm{TMT}\mathrm{TF}{)}_{2}\mathrm{Br},(\mathrm{TMTSF}{)}_{2}\mathrm{PF}{}_{6}$, and $\ensuremath{\alpha}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{T}\mathrm{TF}{)}_{2}M\mathrm{Hg}(\mathrm{SCN}{)}_{4}$ are highly unconventional and coexist w…
Polycrystalline Fe100−xPtx alloy thin films with Pt composition x=25–67 at. % were prepared by dc magnetron sputtering on natural-oxidized silicon wafer substrates, then postannealed in vacuum at various temperatures and over different periods. The effects of film composition, magnetic layer thickness, annealing tempe…
Oxygen-deficient MgO(100) surfaces are studied by means of total-energy calculations, within the density-functional theory. Selected surface configurations presenting increasing densities of neutral oxygen vacancies, ranging from 12.5% to 100%, are considered, the missing oxygen being periodically distributed in the s…
Failure of metallic thin films driven by electromigration is among the most challenging materials reliability problems in microelectronics toward ultra-large-scale integration. One of the most serious failure mechanisms in thin films with bamboo grain structure is the propagation of transgranular voids, which may lead…
In near-bamboo lines, electromigration-induced damage initiates at polygranular clusters which are longer than a critical length and which act as fast-diffusion segments. It has been proposed that two neighboring subcritical clusters can also lead to damage through the interaction of their stress fields. In order to p…
The kinetics of the nucleation and growth of a new phase in the course of a first-order phase transition in a solid is described. The growing center of a new phase is very oblate, because this shape lowers the elastic energy of the deformations which arise due to the difference in the densities of the two phases. An a…
This article reports variations of the leakage current density of Pt/40 nm-(Ba,Sr)TiO3/Pt capacitors after annealing under a N2 atmosphere containing oxygen of about 0.01 ppm. Annealing a capacitor under a N2 atmosphere at 750 °C for 30 min results in an increase of the leakage current density at 1.5 V by more than si…
The complex shear modulus was measured for four low molecular-weight polystyrenes (Mw = 10,500, 5970, 2630, and 1050) near and above the glass transition temperature. For the lowest molecular weight sample, the method of reduced variables, the time–temperature superposition principle, was applicable, while it was not…
Transparent and stoichiometric lead-magnesium-niobate crystals were grown by the Bridgman method. Crystals of centimeter size were obtained without material loss by employing self-seeded and seeded techniques using sealed platinum crucibles. The fastest growth direction was found to be pseudocubic 〈111〉. As-grown crys…
The ceramic compound ${\mathrm{TiB}}_{2}$ has been studied by electron-energy-loss spectroscopy. Spectral shapes in the vicinity of the $\mathrm{B} K$ edge with momentum transfer $\mathbf{q}\ensuremath{\Vert}c$ and $\mathbf{q}\ensuremath{\perp}c$ have been investigated and compared with decomposed, calculated spectra.…
We studied the effect of long-term cropping, fertilisation, and manuring on kinetics of nonexchangeable potassium (K) release from a Tropaquept in 0·01 M CaCl2 and 0·01 M citric acid media under a rice–rice cropping system in an experiment started in 1971. Under continuous cropping, the cumulative K release from the s…