Figure 4

Lateral distribution maps of selected positive secondary ion intensities as macro raster 4 × 4 mm2 show a homogeneous allocation: (a) total positive secondary ions, (b) 65Cu+, (c) Cu3O+, (d) C2H3+, (e) C4H7+, (f) C6H9+ and (g) C7H7+. An accidental particle contaminant was used for adjustment and the grid structure is an artefact of measurement in stitching mode.