Plastic Deformation of Nanometer-Scale Gold Connective Necks.

A combined scanning force and tunneling microscope is used to study the plastic deformation of a connective neck of nanometer dimensions formed by cohesive bonding between metal tip and substrate after contact. The applied force and conductance of the neck are measured simultaneously during the deformation process, which proceeds in alternating elastic and yielding stages. From these data the Young’s modulus and the yield stress of the neck are estimated. This is the first experimental quantitative measurement of plastic deformation in a structure of nanometer size.