Frequency modulated atomic force microscopy on MgO(001) thin films: interpretation of atomic image resolution and distance dependence of tip–sample interaction

M Heyde, M Sterrer, H-P Rust, H-J Freund
2006 Nanotechnology  
Atomically resolved images on a MgO(001) thin film deposited on Ag(001) obtained in ultrahigh vacuum by frequency modulated atomic force microscopy at low temperature are presented and analysed. Images obtained in the attractive regime show a different type of contrast formation from those acquired in the repulsive regime. For the interpretation of the image contrast we have investigated the tip-sample interaction. Force and energy were recovered from frequency shift versus distance curves. The
more » ... istance curves. The derived force curves have been compared to the force laws of long-range, short-range and contact forces. In the attractive regime close to the minimum of the force-distance curve elastic deformations have been confirmed. The recovered energy curve has been scaled to the universal Rydberg model, yielding a decay length of l = 0.3 nm and E = 4.2 aJ (26 eV) for the maximum adhesion energy. A universal binding-energy-distance relation is confirmed for the MgO(001) thin film.
doi:10.1088/0957-4484/17/7/s01 pmid:21727400 fatcat:e3fwlemdj5fc5d4zeczeoykb5e