Mound or pit formation for different tip and surface materials and tip polarity.

1: Element determination by scanning Auger microprobe spectra.2: For triangular voltage pulse. Rectangular pulse used elsewhere.3: Nonconducting liquid between tip and surface.4: Au, Ag, In, Si, Pt, W, C, SiO, MoS or BiSrCaCuO.5: Pit created at larger tip-surface distance, mound at smaller.