Nanometer-scale Mechanical Processing of Muscovite Mica by Atomic Force Microscope

Abstract

Atomic-scale mechanical processing of a layered crystal structure material, muscovite mica was performed using an atomic force microscope (AFM). The atomic scale processing phenomenon was evaluated from lateral force and surface atomic topographic changes caused by sliding. Above about 100 nN load, grooves were formed on the damage-free mica surface. The processing depth dependence on load was evaluated. The depth of the processed grooves increased with load. Processing lateral force estimated from the torsion of the tip beam was divided into plowing force and friction force. The plowing force is proportional to processed depth. Several cycles of mechanical sliding of the tip generated a 1-nm-deep groove by removing potassium from the surfaces which corresponded to the distance from the top surface of SiO₄ to the top surface of the next SiO4 layer beneath it. A groove with four steps of one-nm depth was processed by stepwise mechanical sliding. Atomic images of each step surface of the groove corresponding to the SiO₄ basal plane were observed. Then the letters NIT (scale 2000 × 600 × 1nm) was processed by mechanical tip sliding.