Simple Model for Energy and Force Characteristics of Metallic Nanocontacts
The quantum size oscillations of the energetic properties and the elongation force of the gold slabs and wires, isolated and in a contact with electrodes, are calculated in a free-electron model. A simple relation between the Fermi energy and the square-potential-well depth is used and tested for low-dimensional systems. It is shown that considering the electron subsystem of a slab (or wire) in a contact as open one, the contact acts like a sort of electron pump which sucks or pumps out electrons from the sample. The effect of the contact potential difference on the elastic force oscillations is considered. The calculated amplitudes of force oscillations are in a qualitative agreement with those observed experimentally.