Ubiquitous Mechanisms of Energy Dissipation in Noncontact Atomic Force Microscopy

S. Alireza Ghasemi, Stefan Goedecker, Alexis Baratoff, Thomas Lenosky, Ernst Meyer, Hans J. Hug
2008 Physical Review Letters  
Atomistic simulations considering larger tip structures than hitherto assumed reveal novel dissipation mechanisms in noncontact atomic force microscopy. The potential energy surfaces of realistic silicon tips exhibit many energetically close local minima that correspond to different structures. Most of them easily deform, thus causing dissipation arising from hysteresis in force versus distance characteristics. Furthermore, saddle points which connect local minima can suddenly switch to connect
more » ... y switch to connect different minima. Configurations driven into metastability by the tip motion can thus suddenly access lower energy structures when thennal activation becomes allowed within the time required to detect the resulting average dissipation.
doi:10.1103/physrevlett.100.236106 pmid:18643523 fatcat:nf5mcn2a6vfaxk7qzeiwmby2me