Search results for " XPS"

showing 10 items of 13 documents

Isolated Mn-12 single-molecule magnets grafted on gold surfaces via electrostatic interactions

2005

Electrostatic interactions drive the adsorption of polycationic single-molecule magnets onto anionic monolayers self-assembled on gold surfaces. Well-isolated magnetic clusters have been deposited and characterized using scanning tunneling microscopy and X-ray photoemission spectroscopy.

Photoemission spectroscopyChemistryAnalytical chemistrySTMMolecular nanomagnetsMolecular nanomagnets; Surface; STM; XPSequipment and suppliesElectrostaticslaw.inventionInorganic ChemistrySurfaceCrystallographyAdsorptionX-ray photoelectron spectroscopylawMagnetMonolayerXPSMoleculePhysical and Theoretical ChemistryScanning tunneling microscopehuman activities
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Initial Surface Film on Magnesium Metal. A Characterization by X-ray Photoelectron Spectroscopy (XPS) and Photocurrent Spectroscopy (PCS)

2007

Abstract A detailed investigation of the initial film grown on mechanically polished Mg electrodes has been carried out by ex situ X-ray Photoelectron Spectroscopy (XPS) and in situ Photocurrent Spectroscopy (PCS), allowing to reach a detailed picture of the passive layer structure. The XPS data show that the films formed soon after mechanical treatment and immersion in aqueous electrolyte have a bilayer structure, consisting of an ultra-thin MgO inner layer (∼2.5 nm) and a Mg(OH) 2 external layer. The thickness of the Mg(OH) 2 layer is a function of immersion time and solution temperature. After mechanical treatment and immersion in aqueous solution at room temperature, the MgO/Mg(OH) 2 la…

PhotocurrentChemistryBand gapGeneral Chemical Engineeringcorrosion filmsFermi levelAnalytical chemistryElectrolytemagnesiummagnesium; magnesium hydroxide; XPS; PCS; corrosion filmssymbols.namesakeSettore ING-IND/23 - Chimica Fisica ApplicataX-ray photoelectron spectroscopyPCSElectrochemistrysymbolsXPSSurface layerSpectroscopyLayer (electronics)magnesium hydroxide
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Core-shell Zn-doped TiO2-ZnO nanofibers fabricated via a combination of electrospinning and metal-organic chemical vapour deposition

2010

Zn-doped TiO2 nanofibers shelled with ZnO hierarchical nanoarchitectures have been fabricated combining electrospinning of TiO2 (anatase) nanofibers and metal-organic chemical vapor deposition (MOCVD) of ZnO. The proposed hybrid approach has proven suitable for tailoring both the morphology of the ZnO external shell as well as the crystal structure of the Zn-doped TiO2 core. It has been found that the Zn dopant is incorporated in calcined electrospun nanofibers without any evidence of ZnO aggregates. Effects of different Zn doping levels of Zn-doped TiO2 fibers have been scrutinized and morphological, structural, physico-chemical and optical properties evaluated before and after the hierarc…

AnataseMaterials scienceSettore ING-IND/22 - Scienza e Tecnologia dei MaterialiNanotechnologyCathodoluminescenceChemical vapor depositionNANOWIRESNANOSTRUCTURESZN-DOPINGTITANIA; ELECTROSPINNING; NANOFIBERS; CHEMICAL VAPOUR DEPOSITION ZN-DOPINGROUTEXPSGeneral Materials ScienceMetalorganic vapour phase epitaxyZINC-OXIDENanocompositeDopantELECTROSPINNINGPHOTOCATALYTIC ACTIVITYGeneral ChemistryOPTICAL-PROPERTIESCondensed Matter PhysicsNANOCOMPOSITESElectrospinningCHEMICAL VAPOUR DEPOSITIONNanofiberTITANIAPHOTOLUMINESCENCESENSITIZED SOLAR-CELLSSENSITIZED SOLAR-CELLS; ZINC-OXIDE; PHOTOCATALYTIC ACTIVITY; OPTICAL-PROPERTIES; PHOTOLUMINESCENCE; NANOSTRUCTURES; NANOCOMPOSITES; NANOWIRES; ROUTE; XPSNANOFIBERS
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Chemical modification of carbon nanomaterials (SWCNTs, DWCNTs, MWCNTs and SWCNHs) with diphenyl dichalcogenides

2015

Control over chemical functionalization is a crucial point in the field of nanotechnology. Herein, we present the covalent functionalization of several carbon nanoforms (single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes and carbon nanohorns) by means of diphenyl dichalcogenides. These ones show different reactivity to the nanomaterials and are able to modify their electronic properties depending on the electronegativity of the functionalizing heteroatom. Theoretical calculations were also performed to support the experimental results. All the modified structured nanocarbons were thoroughly characterized by TGA Raman, XPS, UV/Vis/nIR, IR and TEM te…

Chemical substanceMaterials scienceHeteroatomCarbon nanohornSelective chemistry of single-walled nanotubeschemistry.chemical_elementNanotechnologyCarbon nanotubeCarbon nanotubelaw.inventionNanomaterialschalcogenidesymbols.namesakeSWCNTlawGeneral Materials ScienceReactivity (chemistry)Raman spectroscopy XPS spectroscopyCarbon nanomaterials; chemical modificationSettore CHIM/06 - Chimica OrganicaCarbon nanomaterialchemistrysymbolsfunctionalizationCarbon nanomaterialsChemical functionalizationRaman spectroscopychemical modificationCarbon
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Studio del degrado indotto da sali solubili su materiali lapidei nelle ex-carceri dello Steri a Palermo

2009

Steri XPS XRDSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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Tantalum nitride thin film resistors by low temperature reactive sputtering for plastic electronics

2008

This article describes the fabrication and characterisation of tantalum nitride (TaN) thin film for applications in plastic electronics. Thin films of comparable thickness (50-60 nm) have been deposited by RF-magnetron-reactive sputtering at low temperature (100 °C) and their structure and physical (electrical and mechanical) properties have been correlated by using sheet resistance, stress measurements, atomic force microscopy (AFM), XPS, and SIMS. Different film compositions have been obtained by varying the argon to nitrogen flow ratio in the sputtering chamber. XPS showed that 5:1, 2:1 and 1:1 Ar:N 2 ratios gives Ta 2 N, TaN and Ta 3 N 5 phases, respectively. Sheet resistance revealed a…

Materials sciencetantalum nitrideAnalytical chemistryTantalumchemistry.chemical_elementSurfaces and InterfacesGeneral ChemistryCondensed Matter PhysicsGrain sizeSurfaces Coatings and Filmschemistry.chemical_compoundTantalum nitridechemistryX-ray photoelectron spectroscopyElectrical resistivity and conductivitySputteringXPSMaterials ChemistryAFMThin filmplastic electronicsSIMSSheet resistanceplastic electronics tantalum nitride XPS AFMSIMSSurface and Interface Analysis
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Photoelectrochemical and XPS Characterization of Passive films Grown on 316L Stainless Steel in High Temperature Water

2015

One of the major materials challenge for continued safe, reliable and cost-effective utilization of watercooled nuclear reactors for electricity production is development of improved understanding of the synergistic fundamental mechanisms responsible for corrosion and stress corrosion cracking degradation of austenitic steels and nickel base alloys

Settore ING-IND/23 - Chimica Fisica ApplicataPhotoelectrochemical and XPS Characterization Passive films 316L Stainless Steel High Temperature Water
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Plasma Functionalization of Multiwalled Carbon Nanotubes and Their Use in the Preparation of Nylon 6-Based Nanohybrids

2012

The possibility to obtain carbon nanotubes (CNT)/polyamide 6 composites with excellent mechanical properties in a simple, industrially scalable way is investigated. Commercial CNTs are treated by plasma while changing some key parameters (exposure time, plasma power, type of gas) in order to optimize the process and to achieve a sufficient degree of functionalization. The treated samples are characterized by Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The most interesting samples are selected to be used as reinforcing fillers, in different concentrations, in a polyamide 6 matrix. The mechanical tests show a dramatic increase of both tens…

nanoparticlepolymerCarbon nanotubesXPSCarbon nanotubes; xps; Multiwalledplasma etchingMultiwalledcarbon nanotubecarbon nanotubes; nanoparticles; plasma etching; polymers; XPS
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Multiscale Investigation of the Structural, Electrical and Photoluminescence Properties of MoS2 Obtained by MoO3 Sulfurization

2022

In this paper, we report a multiscale investigation of the compositional, morphological, structural, electrical, and optical emission properties of 2H-MoS2 obtained by sulfurization at 800 °C of very thin MoO3 films (with thickness ranging from ~2.8 nm to ~4.2 nm) on a SiO2/Si substrate. XPS analyses confirmed that the sulfurization was very effective in the reduction of the oxide to MoS2, with only a small percentage of residual MoO3 present in the final film. High-resolution TEM/STEM analyses revealed the formation of few (i.e., 2–3 layers) of MoS2 nearly aligned with the SiO2 surface in the case of the thinnest (~2.8 nm) MoO3 film, whereas multilayers of MoS2 partially standing up with r…

SulfurizationGeneral Chemical EngineeringC-AFMMoS<sub>2</sub>; sulfurization; XPS; Raman; TEM; C-AFM; photoluminescenceArticleChemistryMoS<sub>2</sub>TEMXPSGeneral Materials ScienceMoS2QD1-999PhotoluminescenceRamanNanomaterials
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