Topography of defects at atomic resolution using scanning tunneling microscopy

The topography of highly-ordered pyrolytic graphite is studied with scanning tunneling microscopy (STM). Large areas of typically 5 × 5 nm2 were mapped with constant tunneling current and gap voltages from 10 to 700 mV. No clear trigonal symmetry is observed for different samples and tips. Ordered and disordered regions are found and the atomic resolution persists even in the disordered areas. Along one of the principal axes, line dislocations are visible in the topography. Small terraces formed by double-atomic steps are discerned. © 1987.