THE FEASIBILITY OF DETERMINING VACANCY MIGRATION ENERGY BY ATOMIC-FORCE MICROSCOPIC DATA

A computation is performed of the constant force lines and profiles of the lateral force component when scanning the atomic force microscope tip in contact mode above a close-packed surface; containing a vacanc y type defect with allowance for the displacements of the surface atom s. Three different scanning regimes are investigated which may exist f or the different values of the scanning force: without modification of the surface, with a single jump of the defect in opposition to the sc anning direction, and with a ''dragging'' of a vacancy behind atp. it is shown that by the lines of constant force one may conclude what reg ime is actually realized, and that by the profiles of the lateral forc e component one may estimate quantitatively the value of the vacancy m igration energy.