LOCAL-DENSITY OF STATES FROM SPECTROSCOPIC SCANNING-TUNNELING-MICROSCOPE IMAGES - AG(111)

Electron scattering from steps on the Ag(lll) surface has been studied by scanning tunneling microscopy (STM) and spectroscopic STM images o f the differential conductance (dl/dV). The amplitudes and positions o f maxima of dl/dV deviate significantly from those of the local densit y of states (LDOS). These deviations are due to variations of the vert ical tip position which exponentially affect the tunneling barrier tra nsmission and, hence, dl/dV. We show that the LDOS can be recovered fr om simultaneous topographic and spectroscopic measurements.