PSD curves corresponding to the topography and amplitude images shown in Figure 3 as well as of the difference data. Each graph shows the log (PSD[1/λ]) versus log(1/λ) curve for the data acquired at different P/I values. While the different curves are clearly distinguished in the topography (a) and amplitude, (b) PSDs, the curves corresponding to the difference, (c) essentially fall on the same "master curve". The grid lines for the PSD graphs are Δlog[κ] = 1 (horizontal axis) and Δ log[PSD] = 1 (vertical axis).
González Martínez et al. Nanoscale Research Letters 2012 7:174 doi:10.1186/1556-276X-7-174