Browsing by Author "Glatzel, Thilo"

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  • Atomic-scale dissipation processes in dynamic force spectroscopy
    (2011) Kawai, Shigeki; Canova, Filippo Federici; Glatzel, Thilo; Foster, Adam S.; Meyer, Ernst
     School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    A systematic distance-dependent measurement of the quasistatic tip-sample interactions reveals a hidden stochastic dissipative interaction of the atomic-scale contact in dynamic force microscopy. By comparison of experiment with detailed molecular dynamics simulations, we demonstrate that the infrequently observed hysteresis loops are attributed to the formation of atomic chains during tip retraction. These lead to a large magnitude of energy dissipation in a single cycle and dominate the average measured dissipation, while also leading to differences in the forces measured in static and dynamic force microscopy. This paper provides quantitative force measurements and insights into atomic-scale dissipation processes.
  • Energy Loss Triggered by Atomic-Scale Lateral Force
    (2013) Federici Canova, Filippo; Kawai, Shigeki; de Capitani, Christian; Kanno, Ken-ichi; Glatzel, Thilo; Such, Bartosz; Foster, Adam S.; Meyer, Ernst
     School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    We perform bimodal atomic force microscopy measurements on a Br-doped NaCl (001) surface to investigate the mechanisms behind frequency shift and energy dissipation contrasts. The peculiar pattern of the dissipated energy in the torsional channel, related to frictional processes, is increased at the positions of Br impurities, otherwise indistinguishable from Cl ions in the other measured channels. Our simulations reveal how the energy dissipates by the rearrangement of the tip apex and how the process is ultimately governed by lateral forces. Even the slightest change in lateral forces, induced by the presence of a Br impurity, is enough to trigger the apex reconstruction more often, thus increasing the dissipation contrast; the predicted dissipation pattern and magnitude are in good quantitative agreement with the measurements.
  • Measuring Electric Field Induced Subpicometer Displacement of Step Edge Ions
    (2012) Kawai, Shigeki; F. Canova, Filippo; Glatzel, Thilo; Hynninen, Teemu; Meyer, Ernst; Foster, Adam S.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    We provide unambiguous evidence that the applied electrostatic field displaces step atoms of ionic crystal surfaces by subpicometers in different directions via the measurement of the lateral force interactions by bimodal dynamic force microscopy combined with multiscale theoretical simulations. Such a small imbalance in the electrostatic interaction of the shifted anion-cation ions leads to an extraordinary long-range feature potential variation and is now detectable with the extreme sensitivity of the bimodal detection.