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991.
Pt-Ir silicide Schottky diodes were formed by e-beam evaporation of Pt and Ir onto p-Si(100) substrates in high vacuum with
subsequent RTA-annealing at temperatures in the range of 300 to 500 °C. Rutherford Backscattering Spectrometry (RBS) and infrared
photoresponse (PR) measurements were performed to determine the composition and the infrared electrooptical properties of
the resulting films. Coevaporated Pt-Ir films are demixed during silicidation and form a PtSi layer at the interface to the
silicon substrate. The Schottky barrier height is that of a pure PtSi film. Ir deposited prior to Pt exhibits Pt diffusion
through the Ir layer. Only when the Ir film is reacted to IrSi by in situ annealing prior to Pt deposition, a mixed Ir-Pt
silicide Schottky barrier is obtained. Infrared photoemission then yields intermediate Schottky barrier heights between those
of PtSi and IrSi. From a detailed analysis of the photoemission characteristics, it is concluded that the intermediate barrier
height is due to an area average of PtSi and IrSi grains which coexist at the Si interface.
Received: 29 May 1996/Accepted: 12 August 1996 相似文献
992.
A. Wadas M. Dreyer M. Kleiber R. Wiesendanger 《Applied Physics A: Materials Science & Processing》1998,66(4):465-467
Received: 10 December 1997/Accepted: 11 December 1997 相似文献
993.
C. Humbert J.P. Decruppe 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,6(4):511-518
The optical and rheological properties of different viscoelastic solutions of surfactant are studied in order to gather experimental
data used to calculate the value of the stress optical coefficient C. Three surfactants of the same family (CTAB) have been chosen; they differ by the length of the hydrocarbon chain; it concerns
the dodecyltrimethylammonium bromide (C15H34BrN or DoTAB), the myristyltrimethylammonium bromide (C17H38BrN or MyTAB), and the hexadecyltrimethylammonium bromide (C19H42BrN or CTAB). Different parameters like the temperature of the solution and the salinity of the solvent have been made to
vary. Flow birefringence experiments and rheological measurements are performed on these solutions in order to study the dependence
of the extinction angle , of the birefringence intensity and of the shear stress with the shear rate . These data are used to check the stress optical law which turns out to be valid in a wide range of shear rates. The stress
optical coefficient C is then computed: it is found to vary with the salinity of the solvent and the temperature of the solution for a given surfactant.
Then, for all solutions of this work the variations of C are related to the variations of the polarizability anisotropy and the persistence length.
Received: 18 February 1998 / Revised: 23 June 1998 / Accepted: 22 July 1998 相似文献
994.
Results of computer simulations of a 1D particle hopping model of traffic flow are presented. The model is characterized by parallel update and fully asymmetric stochastic hopping dynamics which allows unbounded series of jumps to empty neighbour sites on the right. The considered case of open boundary conditions can be used to model a “bottleneck” situation in traffic. Evidence for self-organized criticality is found in two aspects: the presence of long-range spatial correlations manifested in the shape of density profiles, and long-time temporal correlations showing up in the low-frequency behaviour of the spectral density of the total particle number and flow. A plausible conjecture is to interpret the observed qualitative changes in these features, as a function of the injection rate and the hopping probability, in terms of a nonequilibrium phase transition between a low-density phase and a maximal current phase. This conjecture is supported by the phase diagram obtained in mean-field approximation. 相似文献
995.
996.
I. Josopait L. Dobrek L. Santos A. Sanpera M. Lewenstein 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(3):385-391
The atom optics of Bose-Einstein condensates containing a vortex of circulation one is discussed. We first analyze in detail
the reflection of such a condensate falling on an atomic mirror. In a second part, we consider a rotating condensate in the
case of attractive interactions. We show that for sufficiently large nonlinearity the rotational symmetry of the rotating
condensate is broken.
Received 16 September 2002 / Received in final form 17 November 2002 Published online 11 February 2003 相似文献
997.
A. Bershadskii E. Dremencov D. Fukayama G. Yadid 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,24(3):409-413
Probabilistic properties of spiking time-series obtained in vivo from singular neurons belonging to Red Nucleus of brain are analyzed for two groups of rats: genetically defined rat model
of depression (Flinders Sensitive Rat Line - FSL) and a control (healthy) group. The FSL group shows a distribution of interspike
intervals with a much longer tail than that found for normal rats. The former distribution (for the FSL group) indicates a
power-law with exponent α = - 1±0.1. A simple thermodynamic (noise) model is elaborated to explain obtained results.
Received 13 May 2001 and Received in final form 20 September 2001 相似文献
998.
Ll. Serra A. Puente 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):77-81
The magnetic extension of the Thomas-Fermi-Weizs?cker kinetic energy is used within density-functional-theory to numerically
obtain the ground state densities and energies of two-dimensional quantum dots. The results are thoroughly compared with the
microscopic Kohn-Sham ones in order to assess the validity of the semiclassical method. Circular as well as deformed systems
are considered.
Received 26 October 2000 and Received in final form 14 December 2000 相似文献
999.
T.P. Grozdanov E.A. Solov'ev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,6(1):13-22
The problem of determination of momentum distributions of ejected electrons in slow atomic collisions is studied within the
impact-parameter method by using a dynamic adiabatic basis which takes into account the correct boundary conditions. An expression
is obtained which relates the momentum distribution of the ejected electrons with a coherent sum of the delocalized dynamic
adiabatic eigenstates (elementary wavepackets). The form of the momentum distribution exactly coincides with the form of the total wavepacket in configuration space. General formulas are applied to a model problem of
electron detachment in the process in which the electron-atom interactions are described by the zero-range potentials. In the example considered, the momentum
distribution of ejected electrons, in the center-of-mass frame, exhibits a maximum located in the scattering plane on the
circle of radius (in atomic units), where v is the relative collision velocity and is the impact parameter.
Received: 5 October 1998 相似文献
1000.
Young-Dae Jung 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(2):249-254
In strongly coupled plasmas, the orientation phenomena for direct excitations in electron-hydrogenic ion collisions are investigated using the ion-sphere interaction potential. For small
impact parameters, the orientation parameters have minima which correspond to the complete transitions. The target screening effects slightly increase the probability of populating the 2p-1 state.
Received: 16 December 1998 / Received in final form: 23 March 1999 相似文献