Podgaynyy Nikolay, Wezisla Sabine, Molls Christoph, Iqbal Shahid, Baltruschat Helmut
Institute of Physical and Theoretical Chemistry, University of Bonn, Roemerstrasse 164, D-53117 Bonn, Germany.
Beilstein J Nanotechnol. 2015 Mar 26;6:820-30. doi: 10.3762/bjnano.6.85. eCollection 2015.
Several transitions in the friction coefficient with increasing load are found on Au(111) in sulfuric acid electrolyte containing Cu ions when a monolayer (or submonolayer) of Cu is adsorbed. At the corresponding normal loads, a transition to double or multiple slips in stick-slip friction is observed. The stick length in this case corresponds to multiples of the lattice distance of the adsorbed sulfate, which is adsorbed in a √3 × √7 superstructure on the copper monolayer. Stick-slip behaviour for the copper monolayer as well as for 2/3 coverage can be observed at F N ≥ 15 nN. At this normal load, a change from a small to a large friction coefficient occurs. This leads to the interpretation that the tip penetrates the electrochemical double layer at this point. At the potential (or point) of zero charge (pzc), stick-slip resolution persists at all normal forces investigated.
当在含有铜离子的硫酸电解液中吸附了单层（或亚单层）铜时，在Au(111)上发现摩擦系数随负载增加有几个转变。在相应的法向负载下，观察到在粘滑摩擦中向双滑移或多滑移的转变。在这种情况下，粘滞长度对应于吸附的硫酸盐晶格距离的倍数，该硫酸盐以√3 × √7超结构吸附在铜单层上。当FN≥15 nN时，可以观察到铜单层以及2/3覆盖率的粘滑行为。在这个法向负载下，摩擦系数从小变大。这导致一种解释，即此时尖端穿透了电化学双层。在零电荷电位（或点）(pzc)，在所研究的所有法向力下，粘滑分辨率都持续存在。
