Determination of the surface area of variously polished gold electrodes by scanning tunneling microscopy

Abstract

In order to ascertain the usefulness of scanning tunneling microscopy (STM) in determining surface area, the topography and surface area were measured for four gold foil electrodes prepared by various combinations of mechanical polishing, electropolishing, and annealing. The method of determining surface area is analogous to that used in inscribed rectangles integral approximation. Roughness factors for the gold surfaces were in the range of 1.15 to 1.02, in agreement with literature values obtained by other means for similarly prepared surfaces. STM can be used to determine the surface area of metal or semiconductor surfaces to an accuracy of parts per hundred.