Feasibility and limitation of track studies using atomic force microscopy

Atomic force microscopy (AFM) has been employed to investigate characteristics of tracks of heavy charged particles in solid state nuclear track detectors (SSNTDs). In the present work, we have performed simulations of the track structures revealed by AFM based only on geometrical considerations of the tracks and two types of probes (the ultralever and the ultrahigh aspect ration probe). The purpose of this work is to determine the limitations and constraints of the AFM technique when it is applied to track investigations. The ultralever has comparable dimensions as the tracks in SSNTDs etched for a short time. In some cases, the ultralever is too large or its geometry does not match those of the tracks, so these tracks cannot be scanned properly. In most cases, the ultralever can measure the diameter of the tracks with a rather high precision, but measurements of the depths can be misleading if the track depths are larger than the length of the ultralever. The ultrahigh aspect ratio probe, with an aspect ratio better than 10:1, can record tracks with rather high accuracy if the track depths are not larger than probe length. The technique involving the mounting of nanotubes on AFM tips, which has become available in recent years, should be able to record almost perfect track profiles. 2002 Elsevier Science B.V. All rights reserved.