Search results for "static"
showing 10 items of 1528 documents
A Methodology for the Analysis of Memory Response to Radiation through Bitmap Superposition and Slicing
2015
A methodology is proposed for the statistical analysis of memory radiation test data, with the aim of identifying trends in the single-even upset (SEU) distribution. The treated case study is a 65nm SRAM irradiated with neutrons, protons and heavy-ions.
AC Switching of Relaxor PLZT Ceramics
2005
The switching under application of bipolar ac field is studied by recording of the hysteresis loops in wide temperature and field range in PLZT x/65/35 ceramics. The qualitative difference of the shape of hysteresis loops above and below the freezing temperature is attributed to backswitching in relaxor phase due to the depolarization field produced by the bound charges located at the interphase boundaries. The application of the quasistatic approach to analysis of the experimental data allows us to obtain parameters of the distribution function of local coercive fields from the field dependence of the switching charge derivative on field.
Photoluminescence from strained InAs monolayers in GaAs under pressure
1994
bulk GaAs. At pressures above the band crossover two emission bands are observed. These bands, characterized by having negative pressure coefBcients, are attributed to the type-I transition between conduction-band X „and heavy-hole states of the InAs monolayer and the type-II transition &om X states in GaAs to InAs heavy-hole states. The results are interpreted in terms of tight-binding band-structure calculations for the strained InAs-monolayer — bulk-GaAs system. I. INTRODUCTION Highly strained InAs jGaAs heterostructures have recently attracted interest due to their unusual electronic and optical properties. ~ 4 Epitaxial isomorphic growth of InAs on GaAs can be achieved only up to a sma…
X-ray-diffraction study of the crystal structures and orientational glass state ofAr1−x(N2)xsolid solutions
1990
Solid solutions of ${\mathrm{Ar}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{N}}_{2}$${)}_{\mathit{x}}$ have been investigated by x-ray powder diffraction in the range 0.5x1.0, 8T60 K, and under hydrostatic pressures up to 2200 bars. The structural hcp-cubic (Pa3) phase transition is identified as a martensitic transformation with a wide transformation hysteresis. For x0.8 and T30 K the solid solutions show the orientational glass state, which is characterized by a superposition of inhomogeneous and homogeneous lattice strains. The inhomogeneous component is described by the random-field model. The homogeneous component corresponds to an orthorhombic distortion of the hcp lattice. Two …
Conditions for static friction between flat crystalline surfaces
2000
The conditions for the presence of static friction between two atomically smooth crystalline surfaces are investigated. Commensurate and incommensurate walls are studied. While two commensurate walls always pin at zero lateral force and positive pressures, incommensurate walls only pin if mobile atoms are present in the interface between the surfaces or if the solids are particularly soft. Surprisingly, static friction can be observed between rigid surfaces, either commensurate or incommensurate, that are separated by a freely diffusing fluid layer.
Resonant Rayleigh scattering by confined two-dimensional excitonic states
1997
A systematic study of resonant Rayleigh scattering in semiconductor single quantum wells has been carried out. The dependence of the scattering efficiency on the well width and the temperature has been investigated. The behaviour observed in the resonant Rayleigh spectra can be explained in terms of the confinement of the excitonic states in the plane of the well due to fluctuations in the well width. A microscopic theoretical model for the elastic scattering of light by weakly confined two-dimensional excitonic states has been developed. The Rayleigh scattering efficiency has been calculated to the lowest-order of perturbation theory and the results found to be in good agreement with the e…
Revealing Magnetite Nanoparticles Aggregation Dynamics – A SLS and DLS Study
2010
\(\mathrm{Fe}_{3}\mathrm{O}_{4}\) nanoparticles in aqueous suspensions are not stable but aggregate, tremendously changing the rheological properties of the nanofluid. Modified version of both the Static Light Scattering (SLS) setup and of Dynamic Light Scattering (DLS) setup experiment were used to monitor \(\mathrm{Fe}_{3}\mathrm{O}_{4}\) nanoparticle aggregation in aqueous diluted suspension. The experiments are described in detail and the variation of the average aggregate diameter in time is presented in this work.
Mesoscopic Simulations of Polyelectrolyte Electrophoresis in Nanochannels
2011
We present the results of mesoscopic dissipative particle dynamics (DPD) simulations of coupled electrohydrodynamic phenomena on the micro- and nanoscale. The effects of electroosmotic flow and slippage combined with polyelectrolyte electrophoresis are investigated in detail, taking full account of hydrodynamic and electrostatic interactions. Our numerical results are in excellent agreement with analytical calculations.
Effect of Pressure on Direct Optical Transitions of ?-InSe
2000
We have investigated the effect of hydrostatic pressure on direct optical transitions of the layered semiconductor γ-InSe by photoreflectance (PR) spectroscopy (T = 300 K). In addition, electroreflectance (ER) measurements were performed at ambient pressure. Six structures are resolved in the ER spectra in the energy range from 1.1 to 3.6 eV. The pressure dependence of four of these structures was determined by PR spectroscopy for pressures up to 8 GPa. In order to assign the features observed above the fundamental gap we have carried out band structure calculations for InSe at ambient pressure using a full-potential linear augmented plane wave method. Based on calculated band gap deformati…
Adatom Island Diffusion on Metal Fcc(100) Surfaces
2001
We study the energetics and atomic mechanisms of diffusion of adatom islands on fcc(100) metal surfaces. For small islands, we perform detailed microscopic calculations using semi-empirical embedded-atom model and glue potentials in the case of Cu and Al, respectively. Combining systematic saddle-point search methods and molecular statics simulations allows us to find all the relevant transition paths for island motion. In particular, we demonstrate that there are novel many-body mechanisms such as internal row shearing which can, in some cases, control the island dynamics. Next, we show how using the master equation formalism, diffusion coefficients for small islands up to about five atoms…