Christian Wäckerlin

Learn More
We present a comprehensive study of Er(trensal) single-ion magnets deposited in ultrahigh vacuum onto metallic surfaces. X-ray photoelectron spectroscopy reveals that the molecular structure is preserved after sublimation, and that the molecules are physisorbed on Au(111) while they are chemisorbed on a Ni thin film on Cu(100) single-crystalline surfaces.(More)
The development of chemical systems with switchable molecular spins could lead to the architecture of materials with controllable magnetic or spintronic properties. Here, we present conclusive evidence that the spin of an organometallic molecule coupled to a ferromagnetic substrate can be switched between magnetic off and on states by a chemical stimulus.(More)
Amazing ammonia: The molecular spin state of Ni(II) porphyrin, supported on a ferromagnetic Co surface, can be reversibly switched between spin-off (S = 0) and spin-on (S = 1) states upon coordination and decoordination of the gaseous ligand NH3, respectively (see picture). This finding clearly indicates the possible use of the system as a(More)
On-surface assembly of a spin-bearing and non-aromatic porphyrin-related synthetic Co(II)-complex on a ferromagnetic Ni thin film substrate and subsequent magnetic exchange interaction across the interface were studied by scanning tunnelling microscopy (STM), X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and density(More)
A bottom-up approach is introduced to fabricate two-dimensional self-assembled layers of molecular spin-systems containing Mn and Fe ions arranged in a chessboard lattice. We demonstrate that the Mn and Fe spin states can be reversibly operated by their selective response to coordination/decoordination of volatile ligands like ammonia (NH3).
We investigated the magnetic properties of individual Ho atoms adsorbed on the (111) surface of Pt, which have been recently claimed to display single ion magnetic behavior. By combining x-ray absorption spectroscopy and magnetic dichroism measurements with ligand field multiplet calculations, we reveal a ground state which is incompatible with long spin(More)
A permanent magnet retains a substantial fraction of its saturation magnetization in the absence of an external magnetic field. Realizing magnetic remanence in a single atom allows for storing and processing information in the smallest unit of matter. We show that individual holmium (Ho) atoms adsorbed on ultrathin MgO(100) layers on Ag(100) exhibit(More)
The formation of on-surface coordination polymers is controlled by the interplay of chemical reactivity and structure of the building blocks, as well as by the orientating role of the substrate registry. Beyond the predetermined patterns of structural assembly, the chemical reactivity of the reactants involved may provide alternative pathways in their(More)
Condensation processes are of key importance in nature and play a fundamental role in chemistry and physics. Owing to size effects at the nanoscale, it is conceptually desired to experimentally probe the dependence of condensate structure on the number of constituents one by one. Here we present an approach to study a condensation process atom-by-atom with(More)