Physicists from the University of Regensburg (Germany), the Kanazawa University (Japan) and the Linnaeus University in Kalmar (Sweden) have studied the vibrations of a carbon monoxide molecule (CO, black and red ball in Figure below) that is bonded on a copper surface under the influence of an external force field exerted by the tip of a scanning probe microscope. The measurements were conducted at the University of Regensburg using combined scanning tunneling microscopy, scanning tunneling spectroscopy and atomic force microscopy at liquid helium temperatures and ultrahigh vacuum.
The CO molecule bonds with the carbon atom to the copper underneath and stands upright on the surface such that the oxygen atom points away from the surface.
The CO molecule can oscillate just like an inverted pendulum. The vibration of a molecule on a surface contains critical information on the bond of the molecule with the surface, which is crucial for understanding surface phenomena and for technologically important processes such as catalysis and epitaxial growth.
As expected, the force that originates from the probe tip (pointed object from above in Figure) changes the vibrational frequencies – attractive forces increase the oscillation frequency, and repulsive interactions decrease the oscillation frequency.
The data revealed that the strength of the bond between carbon monoxide and copper was decreasing as the probe tip pulled the molecule away from the surface, marking the direct observation of the weakening of a single atomic bond by an external influence. The result is important as chemical reactions often evolve by loosening an existing bond before forming a new one.
The result of the research has been reported in “Vibrations of a molecule in an external force field” by N. Okabayashi, A. Peronio, M. Paulsson, T. Arai and F. J. Giessibl in Proceedings of the National Academy of Sciences of the United States of America, April xx, 2018, www.pnas.org
Christina Glaser | idw - Informationsdienst Wissenschaft
A torque on conventional magnetic wisdom
23.07.2019 | University of Illinois College of Engineering
MOF@SAW: Nanoquakes and molecular sponges for weighing and separating tiny masses
22.07.2019 | Universität Augsburg
Augsburg chemists and physicists report how they have succeeded in the extremely difficult separation of hydrogen and deuterium in a gas mixture.
Thanks to the Surface Acoustic Wave (SAW) technology developed here and already widely used, the University of Augsburg is internationally recognized as the...
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
23.07.2019 | Life Sciences
23.07.2019 | Life Sciences
23.07.2019 | Physics and Astronomy