Publications by Harald Brune | EPFL Graph Search

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The present tunneling microscopy study reveals that the growth of silver on Pt(111) at substrate temperatures above 620 K results in the formation of a two-dimensional alloy consisting of Ag clusters dissolved in the Pt layer [THETA(Ag)

By combining angle-resolved photoemission spectroscopy and scanning tunneling microscopy we reveal the structural and electronic properties of multilayer graphene on Ru(0001). We prove that large ethylene exposure allows the synthesis of two distinct phase ...

We study the coexistence of strain-and charge-mediated magnetoelectric coupling in a cobalt (0-7 nm) wedge on ferroelectric (011)-oriented Pb(Mg-1/3/Nb-2/3)O-3-PbTiO3 using surface-sensitive x-ray magnetic circular dichroism spectroscopy at the Co L-3,L-2 edges. Three distinct electric field driven remanent magnetization states can be set in the Co film at room temperature. Ab initio density functional theory calculations unravel the relative contributions of both strain and charge to the ob

A novel mechanism for ramified island growth in the initial stages of metal heteroepitaxy is reported. Scanning tunneling microscopy measurements reveal that copper islands on Ni(100), as they grow in size, undergo a shape transition. Below a critical size of approximate to 480 atoms, compact islands form, while above this size they develop a ramified shape. This effect is not of kinetic origin and has been observed in an extended range of growth temperature (250-370 K) and deposition Aux (10(-5)-10(-2) mon

We combine low-temperature scanning tunneling microscopy and measurements of the catalytic activity to establish a structure-reactivity correlation for the CO oxidation on Pt nanoclusters on rutile TiO2(110)-(1 x 1). Annealing of the clusters to 1100 K leads to their encapsulation by a reduced titania layer. We present a method how this catalytically passive strong metal-support interaction state can be transformed into a very active one. We believe that our method is of general interest well beyond the pre

We present the results of temperature-dependent self-assembly of dicarbonitrile-pentaphenyl molecules (NC-Ph-5-CN) on Cu(111). Our low-temperature scanning tunneling microscopy study reveals the formation of metal-organic and purely organic structures, depending on the substrate temperature during deposition (160-300 K), which determines the availability of Cu adatoms at the surface. We use tip functionalization with CO to obtain submolecular resolution and image the coordination atoms, enabling unequivocal

We employ variable-temperature spin-polarized scanning tunneling microscopy in constant current mode to read the magnetic state of monodomain cobalt nanoparticles on Pt(111). In order to avoid stray fields we use in situ prepared antiferromagnetically (Cr) ...

The mechanisms of strain relief in submonolayer heteroepitaxy of Cu/Ni(100) are studied using variable temperature scanning tunneling microscopy and high resolution low energy electron diffraction. It is demonstrated that pseudomorphic copper islands, as they grow in size, undergo a spontaneous shape transition. Below a critical island size of about 500 atoms the islands have a compact shape, while above this size they become ramified. The shape transition of the coherently strained islands, predicted theor

In order to address the interplay of hydrogen bonding, dipolar interactions, and metal coordination, we have investigated the two-dimensional mono- and bicomponent self-assembly of three closely related diaminotriazine-based molecular building blocks and a ...

Self-assembly techniques allow for the fabrication of highly organized architectures with atomic-level precision. Here, we report on molecular-level scanning tunneling microscopy observations demonstrating the supramolecular engineering of complex, regular ...

We have studied the fluoride-bridged Dy-Cr molecular nanomagnet [Dy(hfac)(4)-CrF2(py)(4)]center dot 1/2CHCl(3) by x-ray magnetic circular dichroism (XMCD). The obtained element-specific magnetization curves allow for a quantification of the sign and strength of the magnetic exchange coupling between the Dy and the Cr ions. In an effective spin-1/2 formalism only taking into account the ground Kramers doublet of the Dy-III ion, we find a coupling strength of j (eff,z) = -2.3(1) cm(-1). Further, we find that

By studying the magnetic behavior of self-assembled Co islands on a single-crystal metal surface, Pt(111), we show how the magnetic anisotropy evolves from isolated atoms to monolayer islands and films. Single Co adatoms are found to have a giant magnetocr ...

Achieving fundamental understanding of enantioselective heterogeneous synthesis is marred by the permanent presence of multitudinous arrangements of catalytically active sites in real catalysts. In this study, we address this issue by using structurally co ...

Variable-temperature scanning tunneling microscopy has been applied to study kinetic processes involved in epitaxial growth. This paper concentrates on nucleation and aggregation of submonolayer Ag films on a Pt(lll) surface. From island density versus temperature data, the activation barrier for Ag adatom diffusion as well as the stability of adsorbed Ag dimers are determined. From the adsorbed aggregate shapes conclusions on Ag perimeter diffusion can be drawn. An anisotropy in edge diffusion leads to den

The transformation from pseudomorphic to dislocated and back to pseudomorphic growth with increasing coverage is reported for molecular beam epitaxy of Ag on Pt(111). Below a critical size of 200 Angstrom two-dimensional Ag islands grow coherently strained, while larger islands relieve strain through the introduction of misfit dislocations. Upon completion of the first monolayer, the dislocations disappear and the Ag film again adopts a pseudomorphic structure. With the help of effective-medium theory calcu

X-ray magnetic circular dichroism, atomic multiplet simulations, and density functional theory calculations are employed to identify criteria for the optimum combination of supporting alkaline earth oxide and adsorption site maximizing the spin lifetimes o ...

Atoms and molecules adsorbed on metals affect each other indirectly even over considerable distances. Via systematic density-functional calculations, we establish the nature and strength of such interactions, and explain for what adsorbate systems they critically affect important materials properties. This is verified in kinetic Monte Carlo simulations of epitaxial growth, which help rationalize a number of recent experimental reports on anomalously low diffusion prefactors.

Harald Brune

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Monolayer-Confined Mixing at the Ag-Pt(111) Interface

Magnetic properties of single rare-earth atoms on graphene/Ir(111)

Using metal-organic templates to steer the growth of Fe and Co nanoclusters

Two Distinct Phases of Bilayer Graphene Films on Ru(0001)

Magnetoelectroelastic control of magnetism in an artificial multiferroic

Island shape transition in heteroepitaxial metal growth on square lattices

Overcoming the Strong Metal−Support Interaction State: CO Oxidation on TiO

Temperature-dependent self-assembly of NC–Ph5–CN molecules on Cu(111)

High tunnel magnetoresistance in spin-polarized scanning tunneling microscopy of Co nanoparticles on Pt(111)

Strain relief via island ramification in submonolayer heteroepitaxy

Complex Interplay and Hierarchy of Interactions in Two-Dimensional Supramolecular Assemblies

Chiral kagome lattice from simple ditopic molecular bricks

XMCD study of the magnetic exchange coupling in a fluoride-bridged Dy-Cr molecular cluster

Magnetic anisotropy from single atoms to large monodomain islands of Co/]Pt(111)

Asymmetric azide-alkyne Huisgen cycloaddition on chiral metal surfaces

Kinetic Processes in Metal Epitaxy Studied with Variable-Temperature Stm - Ag/Pt(111)

Giant Spin-Polarization and Magnetic Anisotropy of Nanostructures at Surfaces

Pseudomorphic growth induced by chemical adatom potential

The Impact of Lattice Distortions on the Magnetic Stability of Single Atoms: Dy and Ho on BaO(100)

Nature, strength, and consequences of indirect adsorbate interactions on metals