S. Modesti

Istituto Officina dei Materiali

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

R. Rosei

AREA Science Park

A. Goldoni

Elettra-Sincrotrone Trieste S.C.p.A.

Petra Rudolf

University of Groningen

L. Petaccia

Elettra-Sincrotrone Trieste S.C.p.A.

Erio Tosatti

Scuola Internazionale Superiore di Studi Avanzati

F. Sette

European Synchrotron Radiation Facility

A. Santoni

National Agency for New Technologies, Energy and Sustainable Economic Development

M. Capizzi

Sapienza University of Rome

Cinzia Cepek

Istituto Officina dei Materiali

A. Frova

Sapienza University of Rome

Cooperative Institutions

AREA Science Park

University of Trieste

Elettra-Sincrotrone Trieste S.C.p.A.

Istituto Nazionale per la Fisica della Materia

Federico II University Hospital

Istituto Officina dei Materiali

Sapienza University of Rome

National Research Council

Institute of Structure of Matter

Centre National de la Recherche Scientifique

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Magnetic circular dichroism studies with soft x-rays

AIP conference proceedings (1990)

F. Sette C. T. Chen Yongqing Ma S. Modesti N. V. Smith

Highly monochromatic circularly polarized soft x‐rays are obtained by a simple adaptation of the AT&T Bell Laboratories Dragon beamline to collect synchrotron radiation above an below the storage ring orbit plane. This is demonstrated by the observation of a large magnetic circular dichroism (MCD) effect at the L2,3 absorption edges of ferromagnetic Fe, Co, and Ni. Photoabsorption measurements on ferrites with spinel and garnet structure are also presented, and used to show that MCD measurements allow to determine the presence and the orientation of magnetic moments on specific atoms in compounds.

Monochromatic color

Soft X-rays

10.1063/1.39818

Cite

Citations (17)

Lifetime and screening of the C 1sphotoemission in graphite

Physical review. B, Condensed matter (1990)

F. Sette G. K. Wertheim Yong Ma G. Meigs S. Modesti

High-resolution soft-x-ray photoemission spectra of the C 1s line of graphite have been analyzed to determine the various contributions to the linewidth and line shape. The natural lifetime width \ensuremath{\Gamma} is 210 meV, much larger than those of small molecules (for which \ensuremath{\Gamma}\ensuremath{\simeq}110 meV), or that calculated for the isolated carbon atom (for which \ensuremath{\Gamma}=56 meV). The phonon width is no larger than 50 meV. The general trend toward an enhanced Auger decay rate from the isolated atom to the small molecule and solid is indicative of significant contributions from interatomic Auger processes. However, the large increase in width from molecules to solids must be due to another phenomenon, perhaps to the formation of the excitonic final state in the solids. Our line-shape analysis confirms that the line has an asymmetry like that associated with metallic screening, which had been earlier related to the excitonic final state in graphite, but the singularity index is significantly smaller than that obtained in the previous analysis.

Line (geometry)

Laser linewidth

10.1103/physrevb.41.9766

Cite

Citations (143)

Order-disorder character of the(3×3)to(3×<…

Physical review. B, Condensed matter (2001)

L. Petaccia Luca Floreano A. Goldoni D. Cvetko A. Morgante

Growing attention has been drawn in the past years to the \alpha-phase (1/3 monolayer) of Sn on Ge(111), which undergoes a transition from the low temperature (3x3) phase to the room temperature (\sqrt3 x \sqrt3)R30° one. On the basis of scanning tunnelling microscopy experiments, this transition was claimed to be the manifestation of a surface charge density wave (SCDW), i.e. a periodic redistribution of charge, possibly accompanied by a periodic lattice distortion, which determines a change of the surface symmetry. Recent He diffraction studies of the (3x3) long range order have shown the transition to be of the order-disorder type with a critical temperature Tc=220 K and belonging to the 3-state Potts' universality class. These findings clearly exclude an SCDW driven mechanism at 220 K, but they cannot exclude the occurence of a displacive transition at higher temperature. Here we present photoelectron diffraction data taken at 300 K and photoemission data taken up to 500 K (which is the maximum temperature where the (\sqrt3 x \sqrt3)R30° is stable) . From our analysis it is shown that the atomic structure of the Sn overlayer does not change throughout the transition up to 500 K. As a consequence the displacive hypothesis must be discarded in favour of a genuine order-disorder model.

10.1103/physrevb.64.193410

Cite

Citations (28)

Vibrational spectra of atomic H and D on Cu(110): Evidence for H quantum delocalization

Physical Review Letters (1992)

C. Astaldi Andrea Bianco S. Modesti Erio Tosatti

The vibrational spectra of H on Cu(110) measured with high-resolution energy-loss spectroscopy at very low coverage strongly support the predicted ``protonic'' band structure. Localization is observed for increasing coverage. A simple model qualitatively describes the coverage dependence of the spectra.

10.1103/physrevlett.68.90

Cite

Citations (64)

Thermoreflectance of white tin

Physical review. B, Solid state (1976)

C. Carotenuto E. Colavita S. Modesti M. Sommacal

Thermoreflectivity measurements on thin films of white tin have been carried out in the 0.7-4.0-eV photon energy region at room temperature. The technique has allowed a good resolution of the optical structure arising from interband transitions involving the Fermi surface. Contributions to the modulated absorption were located at 0.83, 0.97, and 1.65 eV in good agreement with previous results of static reflectivity measurements.

Photon energy

10.1103/physrevb.14.5327

Cite

Citations (2)

Computational and experimental imaging of Mn defects on GaAs (110) cross-sectional surfaces

Physical Review B (2007)

Alessandro Stroppa Xiu-Zhi Duan Maria Peressi Davide Furlanetto S. Modesti

We present a combined experimental and computational study of the (110) cross-sectional surface of Mn $\delta$-doped GaAs samples. We focus our study on three different selected Mn defect configurations not previously studied in details, namely surface interstitial Mn, isolated and in pairs, and substitutional Mn atoms on cationic sites (Mn$_{\rm Ga}$) in the first subsurface layer. The sensitivity of the STM images to the specific local environment allows to distinguish between Mn interstitials with nearest neighbor As atoms (Int$_{\rm As}$) rather than Ga atoms (Int$_{\rm Ga}$), and to identify the fingerprint of peculiar satellite features around subsurface substitutional Mn. The simulated STM maps for Int$_{\rm As}$, both isolated and in pairs, and Mn$_{\rm Ga}$ in the first subsurface layer are consistent with some experimental images hitherto not fully characterized.

10.1103/physrevb.75.195335

Cite

Citations (33)

E-h plasma luminescence in GaAs sub(1-x)P sub(x) above direct-indirect crossover

Journal of the Physical Society of Japan (1980)

S. Modesti A. Frova M. Capizzi Lucia G. Quagliano J. L. Staehli

Source

Cite

Citations (5)

Giant Rashba-Splitting of One-Dimensional Metallic States in Bi Dimer Lines on InAs(100)

Nanoscale (2024)

Polina M. Sheverdyaeva Gustav Bihlmayer S. Modesti Vitaliy Feyer Matteo Jugovac

Bismuth produces different types of ordered superstructures on the InAs(100) surface, depending on the growth procedure and coverage. The (2 × 1) phase forms at completion of one Bi monolayer and consists of a uniformly oriented array of parallel lines of Bi dimers. Scanning tunneling and core level spectroscopies demonstrate its metallic character, in contrast with the semiconducting properties expected on the basis of the electron counting principle. The weak electronic coupling among neighboring lines gives rise to quasi one-dimensional Bi-derived bands with open contours at the Fermi level. Spin- and angle-resolved photoelectron spectroscopy reveals a giant Rashba splitting of these bands, in good agreement with

Bismuth

10.1039/d4nr01591f

Cite

Citations (0)

Brillouin-scattering determination of the elastic constants of epitaxial fccC60film

Physical review. B, Condensed matter (1995)

D. Fioretto G. Carlotti G. Socino S. Modesti Cinzia Cepek

Brillouin-light-scattering measurements have been performed on a (111) fcc film of ${\mathrm{C}}_{60}$ (fullerite) epitaxially grown on Ni(110). The Rayleigh surface wave has been detected for propagation along several directions on the film surface and shows an anisotropic behavior consistent with the (111) texture of the film. Bulk acoustic modes have also been measured. The Brillouin data allow the determination of the three independent elastic constants of fcc ${\mathrm{C}}_{60}$. The breakdown of the Cauchy condition indicates intermolecular interactions of non- central character.

Brillouin zone

10.1103/physrevb.52.r8707

Cite

Citations (40)

X-ray Absorption Near Edge Structures of {TmSe} Single Crystal

A. Bianconi S. Stizza S. Modesti K. Fischer M. Campagna

Absorption edge

Source

Cite

Citations (0)