Stability of Tip in Adhesion Process on Atomic Force Microscopy Studied by Coupling Computational Model

Analysis of Tip Stability in Adhesion Process in AFM Using Potential Energy Surface: Stability Versus Dissipation

“…The Mg ion is separated from the O ion when the tip approaches the surface (point 2), whereas a Mg-O ionic bond forms upon retraction from the surface (point 4), even at the same height Z = 5.9Å. This hysteresis of the ionic system produces a nonconservative force on the spring and the energy dissipation in the AFM model [24].…”

“…The oscillation of the spring is concurrently coupled with the motions of the atoms using [24]. The oscillation of the cantilever is described by that of a spring, which is connected to the atomic system of the tip and surface.…”

“…We have investigated the tip stability in the adhesion process using a computational model for AFM, in which the cantilever is described by a spring, and the atomic system of the tip apex and surface is calculated by molecular dynamics [24]. The oscillation of the spring is concurrently coupled with the motions of the atoms using [24].…”

“…The oscillation of the cantilever is described by that of a spring, which is connected to the atomic system of the tip and surface. (b) Two types of ionic structures of the tip used in the atomic system of the AFM model and the time evolutions of the ionic structures upon approach and retraction [24]. The type 1 tip consists of a layer composed of five O (white) ions and four Mg (black) ions at the surface of the MgO crystal with a single Mg ion mounted at the center of this layer.…”

“…Dissipation has been observed in noncontact atomic force microscopy (AFM), and a map of the dissipation shows atomic-scale features for several surfaces [1][2][3][4][5][6][7][8][9]. The origin of dissipation in AFM has been intensively discussed by theoretical and computational methods [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. A stochastic friction mechanism for the dissipation has been proposed [10][11][12][13][14], in which the tip of the cantilever is treated as a Brownian particle fluctuated by random and interaction forces; however, it cannot quantitatively reproduce the dissipation observed in experiments [13,14].…”