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Browsing by Author "Jónsson, Hannes"

Browsing by Author "Jónsson, Hannes"

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  • Maras, E.; Pizzagalli, L.; Ala-Nissila, T.; Jónsson, Hannes (Springer Nature, 2017-09-20)
    Understanding how edge misfit dislocations (MDs) form in a GeSi/Si(001) film has been a long standing issue. The challenge is to find a mechanism accounting for the presence of these dislocations at the interface since they are not mobile and cannot ...
  • Hussain, Javed; Jónsson, Hannes; Skulason, Egill (American Chemical Society (ACS), 2018-04-23)
    CO2 can be reduced electrochemically to form valuable chemicals such as hydrocarbons and alcohols using copper electrodes, whereas the other metal electrodes tested so far mainly form CO or formate, or only the side product, H2. Accurate modeling of ...
  • Maras, Emile; Saito, Mitsuhiro; Inoue, Kazutoshi; Jónsson, Hannes; Ikuhara, Yuichi; McKenna, Keith Patrick (Elsevier BV, 2019-01-15)
    A global optimization procedure is used to predict the structure and electronic properties of the b = c[001] edge dislocation in rutile TiO2. Over 1000 different atomic configurations have been generated using both semi-empirical and density functional ...
  • Müller, Gideon Philipp; Bessarab, Pavel; Vlasov, Sergei M.; Lux, Fabian; Kiselev, Nikolai S.; Blügel, Stefan; Uzdin, Valery M.; Jónsson, Hannes (American Physical Society (APS), 2018-11-06)
    Various transitions that a magnetic Skyrmion can undergo are found in calculations using a method for climbing up the energy surface and converging onto first order saddle points. In addition to collapse and escape through a boundary, the method ...
  • Uzdin, Valery M.; Potkina, Maria; Lobanov, Igor S.; Bessarab, Pavel; Jónsson, Hannes (Elsevier BV, 2017-09)
    The stability of magnetic skyrmions against thermal fluctuations and external perturbations is investigated within the framework of harmonic transition state theory for magnetic degrees of freedom. The influence of confined geometry and atomic scale ...
  • Liashko, Sergei Y; Jónsson, Hannes; Uzdin, Valery M (IOP Publishing, 2017-11-07)
    Transitions between magnetic states of one and two ring kagome spin ice elements consisting of 6 and 11 prolate magnetic islands are calculated and the lifetime of the ground states evaluated using harmonic transition state theory and the stationary ...
  • Kolb, Manuel; Garden, Anna; Badan, Cansin; Garrido Torres, Jose Antonio; Skulason, Egill; Juurlink, Ludo; Jónsson, Hannes; Koper, Marc (Royal Society of Chemistry (RSC), 2019-07-16)
    In this work we compute high-coverage hydrogen adsorption energies and geometries on the stepped platinum surfaces Pt(211) and Pt(533) which contain a (100)-step type and the Pt(221) and Pt(553) surface with a (111) step edge. We discuss these results ...
  • Uzdin, V.M.; Potkina, M.N.; Lobanov, I.S.; Bessarab, Pavel; Jónsson, Hannes (Elsevier BV, 2017-11)
    The stability of skyrmions in various environments is estimated by analyzing the multidimensional surface describing the energy of the system as a function of the directions of the magnetic moments in the system. The energy is given by a Heisenberg-like ...
  • Bessarab, Pavel; Müller, Gideon Philipp; Lobanov, Igor S.; Rybakov, Filipp N.; Kiselev, Nikolai S.; Jónsson, Hannes; Uzdin, Valery M.; Blügel, Stefan; Bergqvist, Lars; Delin, Anna (Springer Nature, 2018-02-21)
    The skyrmion racetrack is a promising concept for future information technology. There, binary bits are carried by nanoscale spin swirls–skyrmions–driven along magnetic strips. Stability of the skyrmions is a critical issue for realising this technology. ...
  • Levi, Gianluca; Biasin, Elisa; Dohn, Asmus O.; Jónsson, Hannes (Royal Society of Chemistry (RSC), 2020)
    Copper(I) bis-phenanthroline complexes represent Earth-abundant alternatives to ruthenium-based sensitizers for solar energy conversion and photocatalysis. Improved understanding of the solvent- mediated excited-state structural dynamics can help ...
  • Pedersen, Andreas; Pizzagalli, Laurent; Jónsson, Hannes (IOP Publishing, 2017-06-15)
    Atomic structure of amorphous silicon consistent with several reported experimental measurements has been obtained from annealing simulations using electron density functional theory calculations and a systematic removal of weakly bound atoms. The ...
  • Kirchhoff, Björn; Braunwarth, Laura; Jung, Christoph; Jónsson, Hannes; Fantauzzi, Donato; Jacob, Timo (Wiley, 2019-12-26)
    Improved understanding of the fundamental processes leading to degradation of platinum nanoparticle electrocatalysts is essential to the continued advancement of their catalytic activity and stability. To this end, the oxidation of platinum nanoparticles ...
  • Levi, Gianluca; Ivanov, Aleksei; Jónsson, Hannes (Royal Society of Chemistry (RSC), 2020-06)
    A direct optimization method for obtaining excited electronic states using density functionals is presented. It involves selective convergence on saddle points on the energy surface representing the variation of the energy as a function of the electronic ...