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Publications associées (284)

Preisach distribution function approach to piezoelectric nonlinearity and hysteresis

The Preisach approach was used to describe the widely observed quadratic field dependence of the direct longitudinal piezoelectric coefficient and its associated hysteresis loop. In this perspective, a four parameters distribution function was put forward ...

2001

Triarylamine on Nanocrystalline TiO2 Studied in Its Reduced and Oxidized State by Photoelectron Spectroscopy

Ulf Anders Hagfeldt

The electronic and mol. structures of an electrochem. reduced and oxidized triarylamine layer (((3-ethyl(p-N,N-dimethylamino)phenyl)amino)propyl-1-phosphonic acid) adsorbed on a nanocryst. TiO2 film have been studied. Photoelectron spectroscopy (PES) measu ...

2001

Central electron temperature enhancements due to sawtooth stabilization during counter electron cyclotron current drive in Tokamak a Configuration Variable

Olivier Sauter, Stefano Coda, Timothy Goodman, Jean-Marc Moret, Holger Reimerdes, Jean-Philippe Hogge, Henri Weisen, Antoine Pochelon, Roland Behn

In the Tokamak a Configuration Variable (TCV), the central electron temperature obtained in discharges with counter (CNTR) electron cyclotron current drive (ECCD) is larger than with CO-ECCD or electron cyclotron resonance heating (ECRH) alone. Comparison ...

2000

Time-resolved spectroscopy of MBE-grown InGaN/GaN self-formed quantum dots

Nicolas Grandjean

GaInN/GaN quantum dots have been grown by molecular beam epitaxy on sapphire substrates. By changing the size and composition of the dots, the emission energy can be tuned over the entire visible spectrum. We present time-resolved photoluminescence obtaine ...

2000

Dynamics of surface migration in the weak corrugation regime

Klaus Kern, Harald Brune

We report a systematic study for metal-on-metal surface migration in the weak corrugation regime, i.e., with migration barriers falling below approximate to 100 meV. The migration characteristics are elucidated by variable-temperature scanning tunneling mi ...

2000

Quantum coherence and lifetimes of surface-state electrons

Klaus Kern, Harald Brune

We discuss a novel approach to measure the electron phase-relaxation length and femtosecond lifetimes at surfaces. It relies on the study of the spatial decay of quantum interference patterns in the local density of states (LDOS) with the STM. The method h ...

2000

Focused electron beam induced deposition of gold

Elyahou Kapon, Patrik Willi Hoffmann, Benjamin Dwir, Ivo Utke, Klaus Leifer

Codeposition of hydrocarbons is a severe problem during focused electron beam writing of pure metal nanostructures. When using organometallic precursors, a low metal content carbonaceous matrix embedding and separating numerous nanosized metal clusters is ...

American Vacuum Society2000

Unpinning of the Au/GaAs interfacial Fermi level by means of ultrathin undoped silicon interlayer inclusion

Giorgio Margaritondo

We present a photoemission spectroscopy study of As-rich n-GaAs(001) surface modified by the deposition of an undoped silicon overlayer with thickness quite narrowly covering the interval from similar to 4 to 25 Angstrom. We observed a nonmonotonic relatio ...

2000

Large Rashba Splitting in InAs Quantum Wells due to Electron Wave Function Penetration into the Barrier Layers

Dirk Grundler

We report on zero-field spin splitting of two-dimensional electron systems. Though absent in the unbiased InAs square asymmetric quantum well (SAQW), the Rashba splitting becomes pronounced by applying a positive back-gate voltage. In our SAQW, the Rashba ...

2000

Tunneling conduction in virgin and fatigued states of PZT films

Nava Setter, Alexander Tagantsev, Igor Stolichnov, Enrico Colla

Fatigued state of the Pt-PZT-Pt system is studied by means of low-temperature conduction measurements. It is shown that the conduction in the temperature interval of 100-140 degrees K is determined by the cold field emission of electrons (tunneling conduct ...

1999

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