Author(s): Josef Grenz, Arne Köhler, Alexander Schwarz, and Roland Wiesendanger
We demonstrate that the magnetic nano-Skyrmion lattice on the Fe monolayer on Ir(111) and the positions of the Fe atoms can be resolved simultaneously using magnetic exchange force microscopy. Thus, the relation between magnetic and atomic structure can be determined straightforwardly by evaluating ...
[Phys. Rev. Lett. 119, 047205] Published Fri Jul 28, 2017
Tunable room-temperature magnetic skyrmions in Ir/Fe/Co/Pt multilayers
Nature Materials, Published online: 17 July 2017; doi:10.1038/nmat4934
A multilayer system based on Ir/Fe/Co/Pt repetitions is found to host magnetic skyrmions at room temperature, while allowing control of the skyrmions’ properties such as size and density.
Author(s): Krisztián Palotás, Levente Rózsa, Eszter Simon, László Udvardi, and László Szunyogh
The correct identification of topological magnetic objects in experiments is an important issue. In the present paper we report on the characterization of metastable skyrmionic spin structures with various topological charges (Q=−3,−2,−1,0,+1,+2) in the (Pt1−xIrx)Fe/Pd(111) ultrathin magnetic film b...
[Phys. Rev. B 96, 024410] Published Mon Jul 10, 2017
Single-molecule quantum dot as a Kondo simulator
Nature Communications, Published online: 30 June 2017; doi:10.1038/ncomms16012
Tuning the structure in the atomic scale enables manipulation of the quantum state in a molecular based system. Here, Hiraoka et al. tune the Kondo coupling between molecular spins and the Au electrode by controlling the position of Fe2+ ions in the molecular cage with a tip.
Maciej.bazarnikDidn't I see that somewhere already?
Nature Materials 16, 505 (2017). doi:10.1038/nmat4900
Authors: Andrea Cornia & Pierre Seneor
Molecular spintronics is an interdisciplinary field at the interface between organic spintronics, molecular magnetism, molecular electronics and quantum computing, which is advancing fast and promises large technological payoffs.
The structural transformation of supramolecular nanostructures with constitutional diversity and adaptability by dynamic coordination chemistry would be of fundamental importance for potential applications in molecular switching devices. The role of halogen doping in the formation of elementary metal–organic motifs on surfaces has not been reported. Now, the 9-ethylguanine molecule (G) and Ni atom, as a model system, are used for the structural transformation and stabilization of metal–organic motifs induced by iodine doping on Au(111). The iodine atoms are homogeneously located at particular hydrogen-rich locations enclosed by G molecules by electrostatic interactions, which would be the key for such an unexpected stabilizing effect. The generality and robustness of this approach are demonstrated in different metal–organic systems (G/Fe) and also by chlorine and bromine.
Safe harbor: The 9-ethylguanine molecule (G) and Ni atoms are used for the structural transformation and stabilization of metal–organic motifs induced by iodine doping on Au(111). The iodine atoms are homogeneously located at particular hydrogen-rich locations enclosed by G molecules by electrostatic interactions. C gray, H white, O red, N blue, I purple, Ni light blue.
Nature Nanotechnology 12, 420 (2017). doi:10.1038/nnano.2017.18
Authors: Taeyoung Choi, William Paul, Steffen Rolf-Pissarczyk, Andrew J. Macdonald, Fabian D. Natterer, Kai Yang, Philip Willke, Christopher P. Lutz & Andreas J. Heinrich
Spin resonance provides the high-energy resolution needed to determine biological and material structures by sensing weak magnetic interactions. In recent years, there have been notable achievements in detecting and coherently controlling individual atomic-scale spin centres for sensitive local magnetometry. However, positioning the spin sensor and characterizing spin–spin interactions with sub-nanometre precision have remained outstanding challenges. Here, we use individual Fe atoms as an electron spin resonance (ESR) sensor in a scanning tunnelling microscope to measure the magnetic field emanating from nearby spins with atomic-scale precision. On artificially built assemblies of magnetic atoms (Fe and Co) on a magnesium oxide surface, we measure that the interaction energy between the ESR sensor and an adatom shows an inverse-cube distance dependence (r−3.01±0.04). This demonstrates that the atoms are predominantly coupled by the magnetic dipole–dipole interaction, which, according to our observations, dominates for atom separations greater than 1 nm. This dipolar sensor can determine the magnetic moments of individual adatoms with high accuracy. The achieved atomic-scale spatial resolution in remote sensing of spins may ultimately allow the structural imaging of individual magnetic molecules, nanostructures and spin-labelled biomolecules.
No researcher is too junior to fix science
Nature 545, 7652 (2017). http://www.nature.com/doifinder/10.1038/545007a
Author: John Tregoning
If young scientists plan to advance their careers before setting the system right, nothing will change, warns John Tregoning.
Nature Materials 16, 507 (2017). doi:10.1038/nmat4902
Authors: Mirko Cinchetti, V. Alek Dediu & Luis E. Hueso
Maciej.bazarniksimilar to a recent paper...
Cis-enediyne-type compounds have received much attention as potent antitumor antibiotics. The conventional synthesis of cis-enediynes in solution typically involves multiple steps and various side reactions. For the first time, selective one-step synthesis of cis-enediyne from a single reactant is reported on a Ag(111) surface with a yield up to 90 %. High selectivity for the formation of cis-enediyne originates from the steric effect posed by weak intermolecular interactions, which protect the cis-enediyne from further reaction. A series of comparative experiments and DFT-based transition-state calculations support the findings. The described synthetic approach for directing reaction pathways on-surface may illuminate potential syntheses of other unstable organic compounds.
Selective on-surface synthesis of cis-enediyne-type compounds is reported for the first time. Bromide-substituted terminal alkynes transform into cis-enediynes on a Ag(111) surface at 420 K. Coadsorbed bromide ions help the formed cis-enediynes aggregate into close-packed islands through Br⋅⋅⋅H bonds, which impose a high steric barrier to further reaction of cis-enediyne.
4,4′-Bis(2,6-difluoropyridin-4-yl)-1,1′:4′,1′′-terphenyl (BDFPTP) molecules underwent dehydrocyclization and covalent coupling reactions on Au(111) according to scanning tunneling microscopy (STM) measurements and density functional theory (DFT) calculations. Self-assembly of the reactants in well-defined molecular domains prior to reaction could greatly enhance the regioselectivity of the dehydrocyclization reaction and suppress defluorinated coupling, demonstrating that self-assembly can efficiently steer on-surface reactions. Such a strategy could be of great importance in surface chemistry and widely applied to control on-surface reactions.
Surface-enhanced selectivity: Randomly distributed 4,4′-bis(2,6-difluoropyridin-4-yl)-1,1′:4′,1′′-terphenyl (BDFPTP) undergoes both dehydrocyclization (DHC) and coupling reactions on Au(111). However, the DHC regioselectivity is greatly enhanced and the coupling reaction is completely suppressed when BDFPTP self-assembles on the surface prior to its reactions.
Maciej.bazarnikCoddy - something you might use?
Maciej.bazarnikFinally published.
Nature Physics 13, 286 (2017). doi:10.1038/nphys3947
Authors: Benjamin E. Feldman, Mallika T. Randeria, Jian Li, Sangjun Jeon, Yonglong Xie, Zhijun Wang, Ilya K. Drozdov, B. Andrei Bernevig & Ali Yazdani
Author(s): Felix Huttmann, David Klar, Nicolae Atodiresei, Carolin Schmitz-Antoniak, Alevtina Smekhova, Antonio J. Martínez-Galera, Vasile Caciuc, Gustav Bihlmayer, Stefan Blügel, Thomas Michely, and Heiko Wende
We create an interface of graphene with a metallic and magnetic support that leaves its electronic structure largely intact. This is achieved by exposing epitaxial graphene on ferromagnetic thin films of Co and Ni to vapor of the rare earth metal Eu at elevated temperatures, resulting in the interca…
[Phys. Rev. B 95, 075427] Published Thu Feb 23, 2017
Author(s): J. van Bree and M. E. Flatté
The spatial resolution of imaging magnetometers has benefited from scanning probe techniques. The requirement that the sample perturbs the scanning probe through a magnetic field external to its volume limits magnetometry to samples with pre-existing magnetization. We propose a magnetometer in which…
[Phys. Rev. Lett. 118, 087601] Published Thu Feb 23, 2017
