Analyses of small facets imaged with scanning-probe microscopy

Two tools for the analysis of facets as detected by scanning-probe microsco py (SPM) images are proposed. One tool is an adaptation of the radial-histo gram transform proposed by D. Schleef in Phys. Rev. B. 55, 2535 (1997). In this article the local slopes in the SPM image are in the present version d etermined by Savitsky-Golay filters with variable lengths [A. Savitsky and M. J. E. Golay, Anal. Chem. 36, 1627 (1964)]. These variable length filters turn out to be important to suppress the influence of noise obscuring the possibility to detect facets and to analyze corrugations with different len gth scales in SPM images, e.g., surface reconstructions. The other tool all ows the direct quantitative determination of the orientation (with a standa rd deviation) of user-specified parts of facets. It makes use of a Savitsky -Golay filter as well. Both tools were applied to an artificially construct ed SPM image and several experimental SFM images showing (ionic) MnO precip itates protruding out of a (metallic) Cu surface. It is shown that the Mill er indices of the facets can be derived experimentally. (C) 1999 American I nstitute of Physics. [S0021-8979(99)04919-1].