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Research paper thumbnail of Elaboration, Characterizations and Energetics of Robust Mo 6 Cluster-Terminated Silicon-Bound Molecular Junctions

The Journal of Physical Chemistry C, 2016

Research paper thumbnail of Single InAs/InP quantum dashes and dots morphology on (001) and (113)B substrates

Research paper thumbnail of Unusual C2 symmetry properties of (In,Ga)As/GaP quantum dots morphology

Research paper thumbnail of Γ-X competition in (In,Ga)As/GaP quantum dots (QDs) : effect of QD size and Indium composition

Research paper thumbnail of gamma-X competition for the optical transition of (In,Ga)As(N)/GaP quantum dots (QDs)

Research paper thumbnail of Covalent attachment of metallic cluster cores (ReSe, MoBr) on silicon (111) surfaces via alkyl chains: surface characterization and electronic properties

Research paper thumbnail of Towards the Local Magnetoconductance Properties of Spin Valves

Research paper thumbnail of Etude des états de défauts à l'interface MgO/GaAs(001)

Research paper thumbnail of Microscopie à émission d'électrons balistiques (BEEM) : Imagerie et Spectroscopie d'interfaces avec une résolution nanométrique

Research paper thumbnail of Using BEEM (Ballistic Electron Emission Microscopy) to probe buried interfaces in metal-organic monolayer-semiconductor hybrid heterostructures

Research paper thumbnail of Dynamics of Substituted Alkyl Monolayers Covalently Bonded to Silicon: A Broadband Admittance Spectroscopy Study

The Journal of Physical Chemistry C, 2014

The relaxation dynamics of surface-bound n-alkyl chains was studied by broadband admittance spect... more The relaxation dynamics of surface-bound n-alkyl chains was studied by broadband admittance spectroscopy (10 mHz−10 MHz) measured at low temperature (130−300 K) in the reverse bias regime of rectifying Hg// organic monolayer (OML)−n-doped Si tunnel junctions. To obtain molecularlevel information on the structure and dynamics of grafted monolayers, carboxyl or amide dipolar moieties were located either at the top free surface with variable acid concentration (0%, 5%, and 100%) or at the inner position in the alkyl backbone (100% amide units). Two classes of dipolar relaxation mechanisms are found with different thermally activated behavior. At low T, only peak A is observed (f ≈ 10 2 −10 5 Hz) with very small activation energy (E A = 20−40 meV) and pre-exponential factor (f 0 A ≈ 10 3 −10 6 Hz). With increasing T, peak B also appears, with higher values of activation energy, E B = 0.25−0.40 eV, and pre-exponential factor ( f 0 B ≈ 10 8 −10 10 Hz). The biasindependent relaxation mechanism A, with very low activation energy typical of dipole−dipole interaction, is attributed to extrinsic relaxation of adventitious H 2 O molecules in hydrogen-bond clusters. Mechanism B is attributed to intrinsic relaxation of the alkyl chain assembly. In the acid series, the relative intensity of peak B is consistent with the acid group coverage given by XPS, in contrast with peak A, and its activation energy reveals increased motional constraints in the acid-substituted OML. The shape of dipolar relaxation peaks, discussed in the framework of Dissado-Hill/Jonscher theories for many-body interactions, is useful to discriminate near-substrate and molecular tail relaxations through order/disorder effects.

Research paper thumbnail of Transverse-momentum selection rules for ballistic electrons at epitaxial metal/GaAs(001) interfaces

Physical Review B, 2010

We report on ballistic electron-emission spectroscopy on high-quality Au (110)/GaAs (001) and Fe ... more We report on ballistic electron-emission spectroscopy on high-quality Au (110)/GaAs (001) and Fe (001)/GaAs (001) Schottky contacts. For the Au (110)/GaAs (001) interface, the ballistic current is characterized by a strong electron injection in the L valley of the GaAs ...

Research paper thumbnail of Influence of oxygen on surface reconstruction and growth of (0 0 1) vanadium

Applied Surface Science, 2001

... References. 1. J. Massies and N. Grandjean. Phys. Rev. Lett. 71 (1993), p. 1411. Full Text vi... more ... References. 1. J. Massies and N. Grandjean. Phys. Rev. Lett. 71 (1993), p. 1411. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (74). 2. J. Fassbender, U. May, B. Schirmer, RM Jungblut, B. Hillebrands and G. Güntherodt. Phys. Rev. Lett. 75 (1995), p. 4476. ...

Research paper thumbnail of Fully epitaxial Fe(110)/MgO(111)/Fe(110) magnetic tunnel junctions: Growth, transport, and spin filtering properties

Applied Physics Letters, 2008

Fully epitaxial Fe͑110͒/MgO͑111͒/Fe͑110͒ magnetic tunnel junctions ͑MTJs͒ have been tested with r... more Fully epitaxial Fe͑110͒/MgO͑111͒/Fe͑110͒ magnetic tunnel junctions ͑MTJs͒ have been tested with respect to symmetry-enforced spin filtering. The Fe͑110͒ electrodes exhibit ⌺ 1↑ and ⌺ 1↓ spin states, both crossing the Fermi level, but with a group velocity about 50% smaller for the minority states compared to the majority ones. These epitaxial but symmetry-mismatched MTJs yield tunneling magnetoresistance ͑TMR͒ values of 54% at 1.5 K and 28% at room temperature. The TMR value and the estimated tunneling spin polarization are consistent with a partial spin filtering due to the ⌺ 1↑ states partially compensated by the ⌺ 1↓ states.

Research paper thumbnail of Work function shifts, Schottky barrier height, and ionization potential determination of thin MgO films on Ag(001)

Applied Physics Letters, 2010

Research paper thumbnail of (In, Ga) As/GaP quantum dots for monolithic integration on silicon

Research paper thumbnail of Optical and Structural Properties of InGaAs/GaAs Heterostructures

Research paper thumbnail of The use of NiMnSb Heusler alloy in MBE Grown Tunnel Junction

Research paper thumbnail of Optical and structural properties of (In,Ga)As/GaP quantum dots : C2 to C2v symmetry transition during the ripening process

Research paper thumbnail of Microscopie à électrons balistiques : des propriétés électroniques locales à l'imagerie magnétique

Research paper thumbnail of Elaboration, Characterizations and Energetics of Robust Mo 6 Cluster-Terminated Silicon-Bound Molecular Junctions

The Journal of Physical Chemistry C, 2016

Research paper thumbnail of Single InAs/InP quantum dashes and dots morphology on (001) and (113)B substrates

Research paper thumbnail of Unusual C2 symmetry properties of (In,Ga)As/GaP quantum dots morphology

Research paper thumbnail of Γ-X competition in (In,Ga)As/GaP quantum dots (QDs) : effect of QD size and Indium composition

Research paper thumbnail of gamma-X competition for the optical transition of (In,Ga)As(N)/GaP quantum dots (QDs)

Research paper thumbnail of Covalent attachment of metallic cluster cores (ReSe, MoBr) on silicon (111) surfaces via alkyl chains: surface characterization and electronic properties

Research paper thumbnail of Towards the Local Magnetoconductance Properties of Spin Valves

Research paper thumbnail of Etude des états de défauts à l'interface MgO/GaAs(001)

Research paper thumbnail of Microscopie à émission d'électrons balistiques (BEEM) : Imagerie et Spectroscopie d'interfaces avec une résolution nanométrique

Research paper thumbnail of Using BEEM (Ballistic Electron Emission Microscopy) to probe buried interfaces in metal-organic monolayer-semiconductor hybrid heterostructures

Research paper thumbnail of Dynamics of Substituted Alkyl Monolayers Covalently Bonded to Silicon: A Broadband Admittance Spectroscopy Study

The Journal of Physical Chemistry C, 2014

The relaxation dynamics of surface-bound n-alkyl chains was studied by broadband admittance spect... more The relaxation dynamics of surface-bound n-alkyl chains was studied by broadband admittance spectroscopy (10 mHz−10 MHz) measured at low temperature (130−300 K) in the reverse bias regime of rectifying Hg// organic monolayer (OML)−n-doped Si tunnel junctions. To obtain molecularlevel information on the structure and dynamics of grafted monolayers, carboxyl or amide dipolar moieties were located either at the top free surface with variable acid concentration (0%, 5%, and 100%) or at the inner position in the alkyl backbone (100% amide units). Two classes of dipolar relaxation mechanisms are found with different thermally activated behavior. At low T, only peak A is observed (f ≈ 10 2 −10 5 Hz) with very small activation energy (E A = 20−40 meV) and pre-exponential factor (f 0 A ≈ 10 3 −10 6 Hz). With increasing T, peak B also appears, with higher values of activation energy, E B = 0.25−0.40 eV, and pre-exponential factor ( f 0 B ≈ 10 8 −10 10 Hz). The biasindependent relaxation mechanism A, with very low activation energy typical of dipole−dipole interaction, is attributed to extrinsic relaxation of adventitious H 2 O molecules in hydrogen-bond clusters. Mechanism B is attributed to intrinsic relaxation of the alkyl chain assembly. In the acid series, the relative intensity of peak B is consistent with the acid group coverage given by XPS, in contrast with peak A, and its activation energy reveals increased motional constraints in the acid-substituted OML. The shape of dipolar relaxation peaks, discussed in the framework of Dissado-Hill/Jonscher theories for many-body interactions, is useful to discriminate near-substrate and molecular tail relaxations through order/disorder effects.

Research paper thumbnail of Transverse-momentum selection rules for ballistic electrons at epitaxial metal/GaAs(001) interfaces

Physical Review B, 2010

We report on ballistic electron-emission spectroscopy on high-quality Au (110)/GaAs (001) and Fe ... more We report on ballistic electron-emission spectroscopy on high-quality Au (110)/GaAs (001) and Fe (001)/GaAs (001) Schottky contacts. For the Au (110)/GaAs (001) interface, the ballistic current is characterized by a strong electron injection in the L valley of the GaAs ...

Research paper thumbnail of Influence of oxygen on surface reconstruction and growth of (0 0 1) vanadium

Applied Surface Science, 2001

... References. 1. J. Massies and N. Grandjean. Phys. Rev. Lett. 71 (1993), p. 1411. Full Text vi... more ... References. 1. J. Massies and N. Grandjean. Phys. Rev. Lett. 71 (1993), p. 1411. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (74). 2. J. Fassbender, U. May, B. Schirmer, RM Jungblut, B. Hillebrands and G. Güntherodt. Phys. Rev. Lett. 75 (1995), p. 4476. ...

Research paper thumbnail of Fully epitaxial Fe(110)/MgO(111)/Fe(110) magnetic tunnel junctions: Growth, transport, and spin filtering properties

Applied Physics Letters, 2008

Fully epitaxial Fe͑110͒/MgO͑111͒/Fe͑110͒ magnetic tunnel junctions ͑MTJs͒ have been tested with r... more Fully epitaxial Fe͑110͒/MgO͑111͒/Fe͑110͒ magnetic tunnel junctions ͑MTJs͒ have been tested with respect to symmetry-enforced spin filtering. The Fe͑110͒ electrodes exhibit ⌺ 1↑ and ⌺ 1↓ spin states, both crossing the Fermi level, but with a group velocity about 50% smaller for the minority states compared to the majority ones. These epitaxial but symmetry-mismatched MTJs yield tunneling magnetoresistance ͑TMR͒ values of 54% at 1.5 K and 28% at room temperature. The TMR value and the estimated tunneling spin polarization are consistent with a partial spin filtering due to the ⌺ 1↑ states partially compensated by the ⌺ 1↓ states.

Research paper thumbnail of Work function shifts, Schottky barrier height, and ionization potential determination of thin MgO films on Ag(001)

Applied Physics Letters, 2010

Research paper thumbnail of (In, Ga) As/GaP quantum dots for monolithic integration on silicon

Research paper thumbnail of Optical and Structural Properties of InGaAs/GaAs Heterostructures

Research paper thumbnail of The use of NiMnSb Heusler alloy in MBE Grown Tunnel Junction

Research paper thumbnail of Optical and structural properties of (In,Ga)As/GaP quantum dots : C2 to C2v symmetry transition during the ripening process

Research paper thumbnail of Microscopie à électrons balistiques : des propriétés électroniques locales à l'imagerie magnétique

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