Luca Bignardi

Spin-dependent electron-phonon coupling in the valence band of single-layer WS2

Nicki Frank Hinsche, Arlette S. Ngankeu, Kevin Guilloy, Sanjoy K. Mahatha, Antonija Grubǐsić Čabo, Marco Bianchi, Maciej Dendzik, Charlotte E. Sanders, Jill A. Miwa, Harsh Bana, Elisabetta Travaglia, Paolo Lacovig, Luca Bignardi, Rosanna Larciprete, Alessandro Baraldi, 4, 6 Silvano Lizzit, Kristian Sommer Thygesen, and Philip Hofmann ∗ Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark† Department of Physics and Astronomy, Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark Physics Department, University of Trieste, Via Valerio 2, 34127 Trieste, Italy Elettra Sincrotrone Trieste S.C.p.A., AREA Science Park, S.S. 14 km 163.5, 34149 Trieste, Italy CNR-Institute for Complex Systems, Via Fosso del Cavaliere 100, 00133 Roma, Italy IOM-CNR, Laboratorio TASC, AREA Science Park, S.S. 14 km 163.5, 34149 Trieste, Italy (Dated: June 20, 2017)

Epitaxial growth of single-orientation high-quality MoS2 monolayers

We present a study on the growth and characterization of high-quality single-layer MoS

A First-principles Study of Stability of Surface Confined Mixed Metal Oxides with Corundum Structure (Fe2O3, Cr2O3, V2O3)

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Exciting H2 Molecules for Graphene Functionalization

with a single orientation, i.e. without the presence of mirror domains. This single orientation of the MoS

An Ordered Mixed Oxide Monolayer Formed by Iron Segregation on Rutile-TiO2(011): Structural Determination by X-ray Photoelectron Diffraction

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Comparison of surface structures of corundum Cr 2 O 3 (0001) and V 2 O 3 (0001) ultrathin films by x-ray photoelectron diffraction

layer is established by means of x-ray photoelectron diffraction. The high quality is evidenced by combining scanning tunneling microscopy with x-ray photoelectron spectroscopy measurements. Spin- and angle-resolved photoemission experiments performed on the sample revealed complete spin-polarization of the valence band states near the K and -K points of the Brillouin zone. These findings open up the possibility to exploit the spin and valley degrees of freedom for encoding and processing information in devices that are based on epitaxially grown materials.

Periodic Modulation of Graphene by a 2D-FeO/Ir(111) Moiré Interlayer

Surface-confined mixed metal oxides can have different chemical properties compared to their host metal oxide support. For this reason, mixed transition metal oxides can offer tunable redox properties. Herein, we use density functional theory to predict the stability of the (0001) surface termination for mixed metal oxides consisting of Fe2O3, Cr2O3 and V2O3. We show that the pure oxide surface stability can predict the surface segregation preference of the surface-confined mixed metal oxides. We focus on substitution of Fe in the V2O3(0001) surface, for which we observe that Fe substitution increases the reducibility of the resulting mixed metal oxide surface. Our results suggest Fe is only stable on the surface under very high temperature and/or low-pressure conditions. Using thermodynamic relationships, we predict the transition points for these surface-confined mixed metal oxides at which exchange between surface/subsurface and subsurface/surface metal atoms occur due to changes in the oxygen chemical potential.

Key role of rotated domains in oxygen intercalation at graphene on Ni(1 1 1)

Hydrogen functionalization of graphene by exposure to vibrationally excited H2 molecules is investigated by combined scanning tunneling microscopy, high-resolution electron energy loss spectroscopy, X-ray photoelectron spectroscopy measurements, and density functional theory calculations. The measurements reveal that vibrationally excited H2 molecules dissociatively adsorb on graphene on Ir(111) resulting in nanopatterned hydrogen functionalization structures. Calculations demonstrate that the presence of the Ir surface below the graphene lowers the H2 dissociative adsorption barrier and allows for the adsorption reaction at energies well below the dissociation threshold of the H–H bond. The first reacting H2 molecule must contain considerable vibrational energy to overcome the dissociative adsorption barrier. However, this initial adsorption further activates the surface resulting in reduced barriers for dissociative adsorption of subsequent H2 molecules. This enables functionalization by H2 molecules with lower vibrational energy, yielding an avalanche effect for the hydrogenation reaction. These results provide an example of a catalytically active graphene-coated surface and additionally set the stage for a re-interpretation of previous experimental work involving elevated H2 background gas pressures in the presence of hot filaments.