S. Valeri

Campus Bio Medico University Hospital

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Document Type

Co-Authors

P. Luches

Istituto Nanoscienze

A. di Bona

Istituto Nanoscienze

A. Rota

University of Modena and Reggio Emilia

Stefania Benedetti

Istituto Nanoscienze

U. del Pennino

University of Modena and Reggio Emilia

Sergio D’Addato

University of Modena and Reggio Emilia

Enrico Gualtieri

University of Modena and Reggio Emilia

S. Altieri

University of Modena and Reggio Emilia

G. Paolicelli

Istituto Nanoscienze

Nicola M. Pugno

Queen Mary University of London

Cooperative Institutions

Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati

243

UCLouvain

158

Roma Tre University

153

European Organization for Nuclear Research

151

Joint Institute for Nuclear Research

138

University of Modena and Reggio Emilia

119

Istituto Nazionale di Fisica Nucleare, Sezione di Pisa

118

Centre National de la Recherche Scientifique

105

University of Pisa

Istituto Nazionale di Fisica Nucleare, Sezione di Napoli

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Hydrolysis atMgO(100)∕Ag(100)oxide-metal interfaces studied by

Physical Review B (2007)

S. Altieri S.F. Contri S. Valeri

Using $\mathrm{O}\phantom{\rule{0.2em}{0ex}}1s$ x-ray photoelectron and Mg $K{L}_{23}{L}_{23}$ Auger spectroscopy, we demonstrate that monolayer $\mathrm{Mg}\mathrm{O}(100)∕\mathrm{Ag}(100)$ exposed at $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ to ${\mathrm{H}}_{2}\mathrm{O}$ vapor pressure of ${10}^{\ensuremath{-}8}\phantom{\rule{0.3em}{0ex}}\text{Torr}$ is strongly hydrated up to 0.8 ${\mathrm{H}}_{2}\mathrm{O}$ per MgO formula unit, half of the water molecules being dissociatively adsorbed at the fourfold coordinated surface oxide sites. These dramatic hydrolysis and molecular adsorption phenomena are strikingly different from those observed at perfect bulklike MgO(100) surfaces, and provide strong experimental support to the concept of unprecedented interactions and properties at oxide-metal interfaces.

10.1103/physrevb.76.205413

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Citations (31)

Structure and morphology of thin MgO films on Mo(001)

Physical Review B (2008)

Stefania Benedetti Piero Torelli S. Valeri Hadj M. Benia Niklas Nilius

Using a combination of reciprocal and real-space techniques, the structural evolution and its effect on the surface morphology is investigated for MgO films of 1--30 ML thickness epitaxially grown on Mo(001). The strain induced by the mismatch with the substrate is relieved between 1 and 7 ML MgO due to the formation of an ordered network of interfacial misfit dislocations aligned along the MgO $⟨110⟩$ directions, particularly evident after annealing the film at 1070 K. A dislocation periodicity of about $60\text{ }\text{\AA{}}$ has been determined by means of grazing incidence x-ray diffraction. The dislocations induce a tilting of the surface that appears in electron diffraction along the $⟨100⟩$ MgO directions for thin films and changes to $⟨110⟩$ directions when the oxide thickness increases. Scanning tunneling microscopy (STM) shows the presence of a regular pattern on the surface below 7 ML thickness associated to the dislocation network. With increasing thickness, screw dislocations connected by nonpolar steps appear on the oxide surface. Thanks to the combination of different diffraction techniques and STM measurements, a comprehensive picture of the relaxation mechanisms in MgO films on Mo(001) can be drawn.

Morphology

10.1103/physrevb.78.195411

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Citations (68)

Effect of calcination temprature on the surface properties of Ti/RuO2-supported Co3O4 layers. A spectroscopic investigation

Colloids and Surfaces (1986)

S. Valeri G. Battaglin G. Lodi S. Trasatti

Surface Modification

10.1016/0166-6622(86)80291-8

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Citations (1)

Local modifications of magnetism and structure in FePt (001) epitaxial thin films by focused ion beam: Two-dimensional perpendicular patterns

Journal of Applied Physics (2008)

F. Albertini L. Nasi F. Casoli S. Fabbrici P. Luches

Focused ion beam was utilized to locally modify magnetism and structure of L10 FePt perpendicular thin films. As a first step, we have performed a magnetic, morphological, and structural study of completely irradiated FePt films with different Ga+ doses (1×1013–4×1016 ions/cm2) and ion beam energy of 30 keV. For doses of 1×1014 ions/cm2 and above a complete transition from the ordered L10 to the disordered A1 phase was found to occur, resulting in a drop of magnetic anisotropy and in the consequent moment reorientation from out-of-plane to in-plane. The lowest effective dose in disordering the structure (1×1014 ions/cm2) was found not to affect the film morphology. Taking advantage of these results, continuous two-dimensional (2D) patterns of perpendicular magnetic structures (250 nm dots, 1 μm dots, 1 μm-large stripes) were produced by focused ion beam without affecting the morphology. The 2D patterns were revealed by means of magnetic force microscopy, that evidenced peculiar domain structures in the case of 1 μm dots.

Magnetism

Magnetic structure

Film plane

10.1063/1.2975217

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Citations (16)

Alkali metals adsorption kinetics on sputtered and cleaved GaAs(110) surfaces

Surface Science (1991)

S. Valeri A. di Bona

Auger electron spectroscopy

Sticking coefficient

Stoichiometry

Reactivity

10.1016/0039-6028(91)91139-o

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Citations (4)

Nitridation by NO Or N₂O of Si-SiO₂ Interfaces

MRS Proceedings (1999)

A. P. Caricato F. Cazzaniga G. F. Cerofolini B. Crivelli M. L. Polignano

Passivation

Photocurrent

10.1557/proc-567-135

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Citations (0)

Soft Tissue Sarcoma with Lower Limb Impairment: Development of a Specific Rehabilitation Protocol Based on Demolitive and Reconstructive Surgery Types

Journal of Clinical Medicine (2024)

Caterina Galluccio Marco Germanotta S. Valeri Beniamino Brunetti Bruno Vincenzi

Soft tissue sarcomas (STSs) are extremely uncommon tumors with a high rate of local recurrence that often require very demolitive surgery. The aim of our study is to propose a specific rehabilitation protocol for patients with STSs, based on the kind of demolition and reconstructive surgery performed, and evaluate its effects.

Reconstructive Surgery

10.3390/jcm13237023

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Citations (2)

Magnetic Dichroism and Spin Structure of Antiferromagnetic NiO(001) Films

Physical Review Letters (2003)

S. Altieri Marco Finazzi H. H. Hsieh H. J. Lin C. T. Chen

We find that Ni L2 edge x-ray magnetic linear dichroism is fully reversed for NiO(001) films on materials with reversed lattice mismatch. We relate this phenomenon to a preferential stabilization of magnetic S domains with main spin component either in or out of the plane, via dipolar interactions. This suggests a way to selectively control spin structures in 3d systems with small spin-orbit coupling.

Non-blocking I/O

Linear dichroism

Dichroism

Magnetic structure

10.1103/physrevlett.91.137201

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Citations (62)

Morphology, Stoichiometry, and Interface Structure of CeO₂ Ultrathin Films on Pt(111)

The Journal of Physical Chemistry C (2011)

P. Luches Federico Pagliuca S. Valeri

Studies of model systems based on cerium oxide are important to improve current understanding of the properties of ceria-based materials, which find wide application based on the ability of cerium oxide to store, release, and transport oxygen. We report a study of CeO2 ultrathin films grown on the Pt(111) surface by reactive deposition of Ce using molecular or atomic oxygen as the oxidizing gas. High-temperature treatments in O2 allowed us to obtain epitaxial structures with a very good quality in terms of morphology, stoichiometry, and structure. The cerium oxide films have a very flat morphology with terraces several tens of nanometers wide. The stoichiometry of the films is mainly CeO2, and the concentration of Ce3+ ions in the film can be reversibly increased by temperature treatments. We propose that the Pt substrate oxidation has a determinant role for the epitaxial stabilization of ceria films.

Stoichiometry

Oxidizing agent

Cerium oxide

Deposition

Morphology

Nanometre

10.1021/jp201139y

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Citations (74)

Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition

Nanotechnology (2015)

Maria Chiara Spadaro Sergio D’Addato P. Luches S. Valeri Vincenzo Grillo

Films of magnetic Ni@NiO core–shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core–shell interface, and magnetic properties. Different values of NiO shell thickness ts could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopy (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field Hbias is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core–shell NPs with desired magnetic properties.

Non-blocking I/O

Exchange bias

10.1088/0957-4484/26/40/405704

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Citations (24)