Publications by Sebastian Stepanow

4 f occupancy and magnetism of rare-earth atoms adsorbed on metal substrates

Harald Brune, Pietro Gambardella, Stefano Rusponi, Sebastian Stepanow, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

We report x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements as well as multiplet calculations for Dy, Ho, Er, and Tm atoms adsorbed on Pt(111), Cu(111), Ag(100), and Ag(111). In the gas phase, all four elements are divalent a ...

Amer Physical Soc2017

Mimicking Enzymatic Active Sites on Surfaces for Energy Conversion Chemistry

Klaus Kern, Sebastian Stepanow, Magalí Alejandra Lingenfelder

Metal organic supramolecular chemistry on surfaces has matured to a point where its underlying growth mechanisms are well understood and structures of defined coordination environments of metal atoms can be synthesized in a controlled and reproducible proc ...

Amer Chemical Soc2015

Modeling Ferro- and Antiferromagnetic Interactions in Metal-Organic Coordination Networks

Klaus Kern, Sebastian Stepanow, Violetta Sessi, Alexander Langner, Tzu-Chun Tseng, Nasiba Abdurakhmanova, Christopher Seiji Kley

Magnetization curves of two rectangular metalorganic coordination networks formed by the organic ligand TCNQ (7,7,8,8-tetracyanoquinodimethane) and two different (Mn and Ni) 3d transition metal atoms [M(3d)] show marked differences that are explained using ...

Amer Chemical Soc2015

Self-assembly of bis(phthalocyaninato) terbium on metal surfaces

Klaus Kern, Sebastian Stepanow, Stephan Rauschenbach

Single-molecule magnets represent the smallest stable magnetic entities available to technology, with promising applications in data storage and quantum computation in sight. Therefore, an interface between devices and single-molecule magnets must be devel ...

Iop Publishing Ltd2015

Atomic-Scale Observation of Multiconformational Binding and Energy Level Alignment of Ruthenium-Based Photosensitizers on TiO2 Anatase

Klaus Kern, Feliciano Giustino, Sebastian Stepanow, Stephan Rauschenbach, Christopher Seiji Kley, Gordon Rinke, Christian Alexander Stephan Dette

Dye-sensitized solar cells constitute a promising approach to sustainable and low-cost solar energy conversion. Their overall efficiency crucially depends on the effective coupling of the photosensitizers to the photoelectrode and the details of the dye's ...

Amer Chemical Soc2014

Convergent and divergent two-dimensional coordination networks formed through substrate-activated or quenched alkynyl ligation

Klaus Kern, Sebastian Stepanow, Christopher Seiji Kley

Metal coordination assemblies of the symmetric bi-functional 4,4'-di-(1,4-buta-1,3-diynyl)-benzoic acid are investigated by scanning tunnelling microscopy on metal surfaces. The formation of long-range ordered, short-range disordered and random phases depe ...

Royal Society of Chemistry2014

Synthesis of wide atomically precise graphene nanoribbons from para-oligophenylene based molecular precursor

Klaus Kern, Sebastian Stepanow, Nasiba Abdurakhmanova

The exploration of graphene nanoribbons (GNRs) and understanding of the structure-property relationship requires the synthesis of GNRs with precisely controllable architecture. In this communication we report on bottom-up fabrication of wide armchair GNR f ...

Pergamon-Elsevier Science Ltd2014

Functionalization of Open Two-Dimensional Metal-Organic Templates through the Selective Incorporation of Metal Atoms

Klaus Kern, Sebastian Stepanow, Christopher Seiji Kley

Surface-confined molecular networks can serve as templates to steer the adsorption and organization of secondary ligands, metal atoms, and clusters. Here, the incorporation of Ni atoms and clusters into open two-dimensional robust metal-organic templates s ...

Amer Chemical Soc2013

Bio-inspired nanocatalysts for the oxygen reduction reaction

Klaus Kern, Sebastian Stepanow, Benjamin Wurster

Electrochemical conversions at fuel cell electrodes are complex processes. In particular, the oxygen reduction reaction has substantial overpotential limiting the electrical power output efficiency. Effective and inexpensive catalytic interfaces are theref ...

Nature Publishing Group2013

Bonding and Charge Transfer in Metal-Organic Coordination Networks on Au(111) with Strong Acceptor Molecules

Klaus Kern, Sebastian Stepanow, Alexander Langner, Nan Jiang

The geometric and electronic structure of two structurally similar metal organic networks grown on the Au(111) surface is investigated by scanning tunnelling microscopy (STM) and spectroscopy (STS) combined with density functional theory (DFT) calculations ...

Amer Chemical Soc2012

Stereoselectivity and electrostatics in charge-transfer Mn- and Cs-TCNQ(4) networks on Ag(100)

Klaus Kern, Sebastian Stepanow, Tzu-Chun Tseng, Nasiba Abdurakhmanova, Andrea Floris

Controlling supramolecular self-assembly is a fundamental step towards molecular nanofabrication, which involves a formidable reverse engineering problem. It is known that a variety of structures are efficiently obtained by assembling appropriate organic m ...

Nature Publishing Group2012

Highly Adaptable Two-Dimensional Metal-Organic Coordination Networks on Metal Surfaces

Klaus Kern, Sebastian Stepanow, Christopher Seiji Kley

The formation of extended two-dimensional metal organic coordination networks (2D-MOCNs) showing high adaptability to surface step edges and structural defects is revealed by scanning tunneling microscopy. Rod-like 4,4'-di-(1,4-buta-1,3-diynyl)-benzoic aci ...

2012

Oxygen Dissociation by Concerted Action of Di-Iron Centers in Metal-Organic Coordination Networks at Surfaces: Modeling Non-Heme Iron Enzymes

Klaus Kern, Pietro Gambardella, Alexandre Dmitriev, Sebastian Stepanow

The high chemical reactivity of unsaturated metal sites is a key factor for the development of novel devices with applications in sensor engineering and catalysis. It is also central in the research for sustainable energy concepts, e.g., the efficient prod ...

American Chemical Society (ACS)2011

Self-Assembled Nanometer-Scale Magnetic Networks on Surfaces: Fundamental Interactions and Functional Properties

Harald Brune, Klaus Kern, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Sebastian Stepanow, Sergio Vlaic

Nanomagnets of controlled size, organized into regular patterns open new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Self-assembling processes on various types of substrates allow designing fine-structured architect ...

Wiley-Blackwell2011

Hierarchical Assembly and Reticulation of Two-Dimensional Mn- and Ni-TCNQ(x) (x=1, 2,4) Coordination Structures on a Metal Surface

Klaus Kern, Sebastian Stepanow, Tzu-Chun Tseng, Nasiba Abdurakhmanova

We report a scanning tunneling microscopy (STM) investigation of the self-assembly of two-dimensional metal-organic coordination networks comprised of Mn or Ni atoms (M) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on a Ag(100) surface. The growth ...

2011

Rational Design of Two-Dimensional Nanoscale Networks by Electrostatic Interactions at Surfaces

Klaus Kern, Sebastian Stepanow

The self-assembly of aromatic carboxylic acids and cesium adatoms on a Cu(100) surface at room temperature has been investigated by scanning tunneling microscopy and X-ray photoelectron spectroscopy. The highly ordered molecular nanostructures are comprise ...

2010

Spin and Orbital Magnetic Moment Anisotropies of Monodispersed Bis(Phthalocyaninato)Terbium on a Copper Surface

Klaus Kern, Pietro Gambardella, Sebastian Stepanow, Stephan Rauschenbach, Violetta Sessi, Tzu-Chun Tseng, Nasiba Abdurakhmanova

The magnetic properties of isolated TbPc2 molecules supported on a Cu(100) surface are investigated by X-ray magnetic circular dichroism at 8 K in magnetic fields up to 5 T. The crystal field and magnetic properties of single molecules are found to be robu ...

2010

Towards the Isomer-Specific Synthesis of Higher Fullerenes and Buckybowls by the Surface-Catalyzed Cyclodehydrogenation of Aromatic Precursors

Klaus Kern, Sebastian Stepanow, Stephan Rauschenbach, Nasiba Abdurakhmanova

Wiley-VCH Verlag GmbH2010

Supramolecular control of the magnetic anisotropy in two-dimensional high-spin Fe arrays at a metal interface

Harald Brune, Klaus Kern, Pietro Gambardella, Sylvain Clair, Alexandre Dmitriev, Sebastian Stepanow, Magalí Alejandra Lingenfelder

Magnetic atoms at surfaces are a rich model system for solid-state magnetic bits exhibiting either classical(1,2) or quantum(3,4) behaviour. Individual atoms, however, are difficult to arrange in regular patterns(1-5). Moreover, their magnetic properties a ...

Nature Publishing Group2009

Low-dimensional supramolecular architectures at metal surfaces

Sebastian Stepanow

This thesis is concerned with supramolecular architectures assembled at metal surfaces. The investigations pursued two objectives. On the one hand, the focus was placed on the fabrication of low-dimensional surface-supported network structures by applying ...

EPFL2005