0000000000859134

AUTHOR

Alessandro Gambardella

showing 4 related works from this author

Scanning tunnelling spectroscopy study of paramagnetic superconducting β''-ET(4)[(H(3)O)Fe(C(2)O(4))(3)]·C(6)H(5)Br crystals.

2010

Scanning tunnelling spectroscopy (STS) and microscopy (STM) were performed on the paramagnetic molecular superconductor β''-ET(4)[(H(3)O)Fe(C(2)O(4))(3)]·C(6)H(5)Br. Under ambient pressure, this compound is located near the boundary separating superconducting and insulating phases of the phase diagram. In spite of a strongly reduced critical temperature T(c) (T(c) = 4.0 K at the onset, zero resistance at T(c) = 0.5 K), the low temperature STS spectra taken in the superconducting regions show strong similarities with the higher T(c) ET κ-derivatives series. We exploited different models for the density of states (DOS), with conventional and unconventional order parameters to take into accoun…

Superconducting coherence lengthSuperconductivityMaterials scienceCondensed matter physicsTransition temperatureOrganic superconductors order parameter scanning tunneling spectroscopyAnalytical chemistryBCS theoryCondensed Matter PhysicsParamagnetismElectrical resistivity and conductivityCondensed Matter::SuperconductivityDensity of statesGeneral Materials SciencePhase diagramJournal of physics. Condensed matter : an Institute of Physics journal
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Electronic and magnetic properties of Mn 12 molecular magnets on sulfonate and carboxylic acid prefunctionalized gold surfaces

2012

Structural, electronic, and magnetic properties of [Mn 12O 12(bet) 16(EtOH) 4](PF 6) 14·4CH 3CN·H 2O (in short Mn 12bet, bet = betaine = +N(CH 3) 3-CH 2-COO -) single-molecule magnets (SMMs) deposited on previously functionalized gold surfaces have been investigated. Self-assembled monolayers (SAMs) either of sodium mercaptoethanesulfonate (MES) or mercaptopropionic acid (MPA) are used as functionalization to avoid the direct interaction between the Mn 12bet molecules and the Au surface with the aim of preserving the main functional properties of the molecules. Scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS) analysis show deposited Mn 12bet SMMs well-isolated …

X-ray absorption spectroscopyAbsorption spectroscopyPhotoemission spectroscopyXMCDElectronic Optical and Magnetic MaterialInorganic chemistrySurfaces Coatings and Filmsurface layerSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialslaw.inventionchemistry.chemical_compoundCrystallographyEnergy (all)General EnergySulfonatechemistryX-ray photoelectron spectroscopylawOxidation stateMonolayerPhysical and Theoretical ChemistryScanning tunneling microscopeMolecular magnets; XMCD; surface layerMolecular magnetsJournal of Physical Chemistry C
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Comparison among superconducting models for β″-ET4[(H3O)Fe(C2O4)3]·C6H5Br single crystals by scanning tunnelling spectroscopy

2008

Single crystals of the novel superconductor beta ''-(BEDT-TTF)(4)[(H3O)Fe(C2O4)(3)]center dot C6H5Br charge-transfer salt were studied using a scanning tunnelling microscope. The measured samples have an onset critical temperature of about 4.0 K. Features often reported on similar compounds were observed in the tunnelling spectra at 1.4 K. STS spectra are compared with several models for the superconducting density of states. Our analysis evidences inhomogeneous superconductivity and indicates that the presence of a magnetic layer into the sample plays a role in determining the superconducting spectroscopic features. (C) 2008 Elsevier Masson SAS. All rights reserved.

SuperconductivityMicroscopeChemistryScanning electron microscopeScanning tunneling spectroscopyAnalytical chemistrysuperconductivity organic materialsBEDT-TTF Organic superconductors Scanning tunnelling microscopy and spectroscopy Abrikosov Gorkov theoryGeneral ChemistryCondensed Matter Physicslaw.inventionOrganic superconductorsTunnel effectScanning tunnelling microscopy and spectroscopylawCondensed Matter::SuperconductivityDensity of statesGeneral Materials ScienceScanning tunneling microscopeBEDT-TTFQuantum tunnellingSolid State Sciences
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A novel picture for charge transport interpretation in epitaxial manganite thin films

2013

Transport characterizations of epitaxial La0.7Sr0.3MnO3 thin films in the thickness range 5-40 nm and 25-410 K temperature interval have been accurately collected. We show that taking into account polaronic effects allows to achieve the best ever fitting of the transport curves in the whole temperature range. The Current Carriers Density Collapse picture accurately accounts for the properties variation across the metal-insulator-transition. The electron-phonon coupling parameter estimations are in a good agreement with theoretical predictions. The results promote a clear and straightforward quantitative description of the manganite films involved in charge transport device applications.

Condensed Matter - Strongly Correlated ElectronsCondensed Matter - Materials ScienceStrongly Correlated Electrons (cond-mat.str-el)Materials Science (cond-mat.mtrl-sci)FOS: Physical sciences
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