MEASURING THE FRACTAL DIMENSION WITH STM - APPLICATION TO VACUUM-EVAPORATED GOLD

Recently, two methods, i.e. the area-perimeter and the Fourier transform, have been used to obtain the fractal dimension of rough surfaces from digitized STM images. In this work, we have tested both methods with several computer-simulated surfaces. For typical file sizes used in STM, the area-perimeter method yields better results than the Fourier transform method. We have also performed extended measurements to obtain the fractal dimension of vacuum-evaporated gold films. The area-perimeter method gives a fractal dimension, D', equal to 1.72 +/- 0.05, in good agreement with the value expected from ballistic deposition models.