Mechanical Engineering Commons^™

Suppression Of Atomic Friction Under Cryogenic Conditions: The Role Of Athermal Instability In Afm Measurements, Yalin Dong, Hongyu Gao, Ashlie Martini

Dr. Yalin Dong

A theoretical investigation of the behavior of atomic friction at low temperatures is performed using a master equation method with a two-mass, two-spring Prandtl-Tomlinson model of an atomic force microscope experiment. A novel approach is taken in which two distinct instability mechanisms are introduced into the model: thermal activation is described by transition state theory with a prefactor associated with the frequency of the tip apex, and athermal instability is introduced by an Arrhenius-like equation with a prefactor associated with the characteristic frequency of the cantilever. Thermal instability causes the often reported decrease of friction with temperature followed by a …